In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: fix usage slab after free [ +0.000021] BUG: KASAN: slab-use-after-free in drm_sched_entity_flush+0x6cb/0x7a0 [gpu_sched] [ +0.000027] Read of size 8 at addr ffff8881b8605f88 by task amd_pci_unplug/2147 [ +0.000023] CPU: 6 PID: 2147 Comm: amd_pci_unplug Not tainted 6.10.0+ #1 [ +0.000016] Hardware name: ASUS System Product Name/ROG STRIX B550-F GAMING (WI-FI), BIOS 1401 12/03/2020 [ +0.000016] Call Trace: [ +0.000008] <TASK> [ +0.000009] dump_stack_lvl+0x76/0xa0 [ +0.000017] print_report+0xce/0x5f0 [ +0.000017] ? drm_sched_entity_flush+0x6cb/0x7a0 [gpu_sched] [ +0.000019] ? srso_return_thunk+0x5/0x5f [ +0.000015] ? kasan_complete_mode_report_info+0x72/0x200 [ +0.000016] ? drm_sched_entity_flush+0x6cb/0x7a0 [gpu_sched] [ +0.000019] kasan_report+0xbe/0x110 [ +0.000015] ? drm_sched_entity_flush+0x6cb/0x7a0 [gpu_sched] [ +0.000023] __asan_report_load8_noabort+0x14/0x30 [ +0.000014] drm_sched_entity_flush+0x6cb/0x7a0 [gpu_sched] [ +0.000020] ? srso_return_thunk+0x5/0x5f [ +0.000013] ? __kasan_check_write+0x14/0x30 [ +0.000016] ? __pfx_drm_sched_entity_flush+0x10/0x10 [gpu_sched] [ +0.000020] ? srso_return_thunk+0x5/0x5f [ +0.000013] ? __kasan_check_write+0x14/0x30 [ +0.000013] ? srso_return_thunk+0x5/0x5f [ +0.000013] ? enable_work+0x124/0x220 [ +0.000015] ? __pfx_enable_work+0x10/0x10 [ +0.000013] ? srso_return_thunk+0x5/0x5f [ +0.000014] ? free_large_kmalloc+0x85/0xf0 [ +0.000016] drm_sched_entity_destroy+0x18/0x30 [gpu_sched] [ +0.000020] amdgpu_vce_sw_fini+0x55/0x170 [amdgpu] [ +0.000735] ? __kasan_check_read+0x11/0x20 [ +0.000016] vce_v4_0_sw_fini+0x80/0x110 [amdgpu] [ +0.000726] amdgpu_device_fini_sw+0x331/0xfc0 [amdgpu] [ +0.000679] ? mutex_unlock+0x80/0xe0 [ +0.000017] ? __pfx_amdgpu_device_fini_sw+0x10/0x10 [amdgpu] [ +0.000662] ? srso_return_thunk+0x5/0x5f [ +0.000014] ? __kasan_check_write+0x14/0x30 [ +0.000013] ? srso_return_thunk+0x5/0x5f [ +0.000013] ? mutex_unlock+0x80/0xe0 [ +0.000016] amdgpu_driver_release_kms+0x16/0x80 [amdgpu] [ +0.000663] drm_minor_release+0xc9/0x140 [drm] [ +0.000081] drm_release+0x1fd/0x390 [drm] [ +0.000082] __fput+0x36c/0xad0 [ +0.000018] __fput_sync+0x3c/0x50 [ +0.000014] __x64_sys_close+0x7d/0xe0 [ +0.000014] x64_sys_call+0x1bc6/0x2680 [ +0.000014] do_syscall_64+0x70/0x130 [ +0.000014] ? srso_return_thunk+0x5/0x5f [ +0.000014] ? irqentry_exit_to_user_mode+0x60/0x190 [ +0.000015] ? srso_return_thunk+0x5/0x5f [ +0.000014] ? irqentry_exit+0x43/0x50 [ +0.000012] ? srso_return_thunk+0x5/0x5f [ +0.000013] ? exc_page_fault+0x7c/0x110 [ +0.000015] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ +0.000014] RIP: 0033:0x7ffff7b14f67 [ +0.000013] Code: ff e8 0d 16 02 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 41 c3 48 83 ec 18 89 7c 24 0c e8 73 ba f7 ff [ +0.000026] RSP: 002b:00007fffffffe378 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ +0.000019] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ffff7b14f67 [ +0.000014] RDX: 0000000000000000 RSI: 00007ffff7f6f47a RDI: 0000000000000003 [ +0.000014] RBP: 00007fffffffe3a0 R08: 0000555555569890 R09: 0000000000000000 [ +0.000014] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fffffffe5c8 [ +0.000013] R13: 00005555555552a9 R14: 0000555555557d48 R15: 00007ffff7ffd040 [ +0.000020] </TASK> [ +0.000016] Allocated by task 383 on cpu 7 at 26.880319s: [ +0.000014] kasan_save_stack+0x28/0x60 [ +0.000008] kasan_save_track+0x18/0x70 [ +0.000007] kasan_save_alloc_info+0x38/0x60 [ +0.000007] __kasan_kmalloc+0xc1/0xd0 [ +0.000007] kmalloc_trace_noprof+0x180/0x380 [ +0.000007] drm_sched_init+0x411/0xec0 [gpu_sched] [ +0.000012] amdgpu_device_init+0x695f/0xa610 [amdgpu] [ +0.000658] amdgpu_driver_load_kms+0x1a/0x120 [amdgpu] [ +0.000662] amdgpu_pci_p ---truncated---

In the Linux kernel, the following vulnerability has been resolved: bus: mhi: core: Fix invalid error returning in mhi_queue mhi_queue returns an error when the doorbell is not accessible in the current state. This can happen when the device is in non M0 state, like M3, and needs to be waken-up prior ringing the DB. This case is managed earlier by triggering an asynchronous M3 exit via controller resume/suspend callbacks, that in turn will cause M0 transition and DB update. So, since it's not an error but just delaying of doorbell update, there is no reason to return an error. This also fixes a use after free error for skb case, indeed a caller queuing skb will try to free the skb if the queueing fails, but in that case queueing has been done.

In the Linux kernel, the following vulnerability has been resolved: nfsd: make sure exp active before svc_export_show The function `e_show` was called with protection from RCU. This only ensures that `exp` will not be freed. Therefore, the reference count for `exp` can drop to zero, which will trigger a refcount use-after-free warning when `exp_get` is called. To resolve this issue, use `cache_get_rcu` to ensure that `exp` remains active. ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 3 PID: 819 at lib/refcount.c:25 refcount_warn_saturate+0xb1/0x120 CPU: 3 UID: 0 PID: 819 Comm: cat Not tainted 6.12.0-rc3+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.1-2.fc37 04/01/2014 RIP: 0010:refcount_warn_saturate+0xb1/0x120 ... Call Trace: <TASK> e_show+0x20b/0x230 [nfsd] seq_read_iter+0x589/0x770 seq_read+0x1e5/0x270 vfs_read+0x125/0x530 ksys_read+0xc1/0x160 do_syscall_64+0x5f/0x170 entry_SYSCALL_64_after_hwframe+0x76/0x7e

In the Linux kernel, the following vulnerability has been resolved: ext4: fix possible UAF when remounting r/o a mmp-protected file system After commit 618f003199c6 ("ext4: fix memory leak in ext4_fill_super"), after the file system is remounted read-only, there is a race where the kmmpd thread can exit, causing sbi->s_mmp_tsk to point at freed memory, which the call to ext4_stop_mmpd() can trip over. Fix this by only allowing kmmpd() to exit when it is stopped via ext4_stop_mmpd(). Bug-Report-Link: <20210629143603.2166962-1-yebin10@huawei.com>

In the Linux kernel, the following vulnerability has been resolved: net: ieee802154: do not leave a dangling sk pointer in ieee802154_create() sock_init_data() attaches the allocated sk object to the provided sock object. If ieee802154_create() fails later, the allocated sk object is freed, but the dangling pointer remains in the provided sock object, which may allow use-after-free. Clear the sk pointer in the sock object on error.

In the Linux kernel, the following vulnerability has been resolved: net: af_can: do not leave a dangling sk pointer in can_create() On error can_create() frees the allocated sk object, but sock_init_data() has already attached it to the provided sock object. This will leave a dangling sk pointer in the sock object and may cause use-after-free later.

In the Linux kernel, the following vulnerability has been resolved: ACPI: custom_method: fix potential use-after-free issue In cm_write(), buf is always freed when reaching the end of the function. If the requested count is less than table.length, the allocated buffer will be freed but subsequent calls to cm_write() will still try to access it. Remove the unconditional kfree(buf) at the end of the function and set the buf to NULL in the -EINVAL error path to match the rest of function.

In the Linux kernel, the following vulnerability has been resolved: regmap: set debugfs_name to NULL after it is freed There is a upstream commit cffa4b2122f5("regmap:debugfs: Fix a memory leak when calling regmap_attach_dev") that adds a if condition when create name for debugfs_name. With below function invoking logical, debugfs_name is freed in regmap_debugfs_exit(), but it is not created again because of the if condition introduced by above commit. regmap_reinit_cache() regmap_debugfs_exit() ... regmap_debugfs_init() So, set debugfs_name to NULL after it is freed.

Use-after-free vulnerability in fs/crypto/ in the Linux kernel before 4.10.7 allows local users to cause a denial of service (NULL pointer dereference) or possibly gain privileges by revoking keyring keys being used for ext4, f2fs, or ubifs encryption, causing cryptographic transform objects to be freed prematurely.

In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: bsg: Set bsg_queue to NULL after removal Currently, this does not cause any issues, but I believe it is necessary to set bsg_queue to NULL after removing it to prevent potential use-after-free (UAF) access.

In function msm_pcm_playback_close() in all Android releases from CAF using the Linux kernel, prtd is assigned substream->runtime->private_data. Later, prtd is freed. However, prtd is not sanitized and set to NULL, resulting in a dangling pointer. There are other functions that access the same memory (substream->runtime->private_data) with a NULL check, such as msm_pcm_volume_ctl_put(), which means this freed memory could be used.

In the Linux kernel, the following vulnerability has been resolved: drm: bridge/panel: Cleanup connector on bridge detach If we don't call drm_connector_cleanup() manually in panel_bridge_detach(), the connector will be cleaned up with the other DRM objects in the call to drm_mode_config_cleanup(). However, since our drm_connector is devm-allocated, by the time drm_mode_config_cleanup() will be called, our connector will be long gone. Therefore, the connector must be cleaned up when the bridge is detached to avoid use-after-free conditions. v2: Cleanup connector only if it was created v3: Add FIXME v4: (Use connector->dev) directly in if() block

In the Linux kernel, the following vulnerability has been resolved: net: fix use-after-free in tw_timer_handler A real world panic issue was found as follow in Linux 5.4. BUG: unable to handle page fault for address: ffffde49a863de28 PGD 7e6fe62067 P4D 7e6fe62067 PUD 7e6fe63067 PMD f51e064067 PTE 0 RIP: 0010:tw_timer_handler+0x20/0x40 Call Trace: <IRQ> call_timer_fn+0x2b/0x120 run_timer_softirq+0x1ef/0x450 __do_softirq+0x10d/0x2b8 irq_exit+0xc7/0xd0 smp_apic_timer_interrupt+0x68/0x120 apic_timer_interrupt+0xf/0x20 This issue was also reported since 2017 in the thread [1], unfortunately, the issue was still can be reproduced after fixing DCCP. The ipv4_mib_exit_net is called before tcp_sk_exit_batch when a net namespace is destroyed since tcp_sk_ops is registered befrore ipv4_mib_ops, which means tcp_sk_ops is in the front of ipv4_mib_ops in the list of pernet_list. There will be a use-after-free on net->mib.net_statistics in tw_timer_handler after ipv4_mib_exit_net if there are some inflight time-wait timers. This bug is not introduced by commit f2bf415cfed7 ("mib: add net to NET_ADD_STATS_BH") since the net_statistics is a global variable instead of dynamic allocation and freeing. Actually, commit 61a7e26028b9 ("mib: put net statistics on struct net") introduces the bug since it put net statistics on struct net and free it when net namespace is destroyed. Moving init_ipv4_mibs() to the front of tcp_init() to fix this bug and replace pr_crit() with panic() since continuing is meaningless when init_ipv4_mibs() fails. [1] https://groups.google.com/g/syzkaller/c/p1tn-_Kc6l4/m/smuL_FMAAgAJ?pli=1

In the Linux kernel, the following vulnerability has been resolved: firmware: arm_scmi: Fix slab-use-after-free in scmi_bus_notifier() The scmi_dev->name is released prematurely in __scmi_device_destroy(), which causes slab-use-after-free when accessing scmi_dev->name in scmi_bus_notifier(). So move the release of scmi_dev->name to scmi_device_release() to avoid slab-use-after-free. | BUG: KASAN: slab-use-after-free in strncmp+0xe4/0xec | Read of size 1 at addr ffffff80a482bcc0 by task swapper/0/1 | | CPU: 1 PID: 1 Comm: swapper/0 Not tainted 6.6.38-debug #1 | Hardware name: Qualcomm Technologies, Inc. SA8775P Ride (DT) | Call trace: | dump_backtrace+0x94/0x114 | show_stack+0x18/0x24 | dump_stack_lvl+0x48/0x60 | print_report+0xf4/0x5b0 | kasan_report+0xa4/0xec | __asan_report_load1_noabort+0x20/0x2c | strncmp+0xe4/0xec | scmi_bus_notifier+0x5c/0x54c | notifier_call_chain+0xb4/0x31c | blocking_notifier_call_chain+0x68/0x9c | bus_notify+0x54/0x78 | device_del+0x1bc/0x840 | device_unregister+0x20/0xb4 | __scmi_device_destroy+0xac/0x280 | scmi_device_destroy+0x94/0xd0 | scmi_chan_setup+0x524/0x750 | scmi_probe+0x7fc/0x1508 | platform_probe+0xc4/0x19c | really_probe+0x32c/0x99c | __driver_probe_device+0x15c/0x3c4 | driver_probe_device+0x5c/0x170 | __driver_attach+0x1c8/0x440 | bus_for_each_dev+0xf4/0x178 | driver_attach+0x3c/0x58 | bus_add_driver+0x234/0x4d4 | driver_register+0xf4/0x3c0 | __platform_driver_register+0x60/0x88 | scmi_driver_init+0xb0/0x104 | do_one_initcall+0xb4/0x664 | kernel_init_freeable+0x3c8/0x894 | kernel_init+0x24/0x1e8 | ret_from_fork+0x10/0x20 | | Allocated by task 1: | kasan_save_stack+0x2c/0x54 | kasan_set_track+0x2c/0x40 | kasan_save_alloc_info+0x24/0x34 | __kasan_kmalloc+0xa0/0xb8 | __kmalloc_node_track_caller+0x6c/0x104 | kstrdup+0x48/0x84 | kstrdup_const+0x34/0x40 | __scmi_device_create.part.0+0x8c/0x408 | scmi_device_create+0x104/0x370 | scmi_chan_setup+0x2a0/0x750 | scmi_probe+0x7fc/0x1508 | platform_probe+0xc4/0x19c | really_probe+0x32c/0x99c | __driver_probe_device+0x15c/0x3c4 | driver_probe_device+0x5c/0x170 | __driver_attach+0x1c8/0x440 | bus_for_each_dev+0xf4/0x178 | driver_attach+0x3c/0x58 | bus_add_driver+0x234/0x4d4 | driver_register+0xf4/0x3c0 | __platform_driver_register+0x60/0x88 | scmi_driver_init+0xb0/0x104 | do_one_initcall+0xb4/0x664 | kernel_init_freeable+0x3c8/0x894 | kernel_init+0x24/0x1e8 | ret_from_fork+0x10/0x20 | | Freed by task 1: | kasan_save_stack+0x2c/0x54 | kasan_set_track+0x2c/0x40 | kasan_save_free_info+0x38/0x5c | __kasan_slab_free+0xe8/0x164 | __kmem_cache_free+0x11c/0x230 | kfree+0x70/0x130 | kfree_const+0x20/0x40 | __scmi_device_destroy+0x70/0x280 | scmi_device_destroy+0x94/0xd0 | scmi_chan_setup+0x524/0x750 | scmi_probe+0x7fc/0x1508 | platform_probe+0xc4/0x19c | really_probe+0x32c/0x99c | __driver_probe_device+0x15c/0x3c4 | driver_probe_device+0x5c/0x170 | __driver_attach+0x1c8/0x440 | bus_for_each_dev+0xf4/0x178 | driver_attach+0x3c/0x58 | bus_add_driver+0x234/0x4d4 | driver_register+0xf4/0x3c0 | __platform_driver_register+0x60/0x88 | scmi_driver_init+0xb0/0x104 | do_one_initcall+0xb4/0x664 | kernel_init_freeable+0x3c8/0x894 | kernel_init+0x24/0x1e8 | ret_from_fork+0x10/0x20

In the Linux kernel, the following vulnerability has been resolved: ubifs: authentication: Fix use-after-free in ubifs_tnc_end_commit After an insertion in TNC, the tree might split and cause a node to change its `znode->parent`. A further deletion of other nodes in the tree (which also could free the nodes), the aforementioned node's `znode->cparent` could still point to a freed node. This `znode->cparent` may not be updated when getting nodes to commit in `ubifs_tnc_start_commit()`. This could then trigger a use-after-free when accessing the `znode->cparent` in `write_index()` in `ubifs_tnc_end_commit()`. This can be triggered by running rm -f /etc/test-file.bin dd if=/dev/urandom of=/etc/test-file.bin bs=1M count=60 conv=fsync in a loop, and with `CONFIG_UBIFS_FS_AUTHENTICATION`. KASAN then reports: BUG: KASAN: use-after-free in ubifs_tnc_end_commit+0xa5c/0x1950 Write of size 32 at addr ffffff800a3af86c by task ubifs_bgt0_20/153 Call trace: dump_backtrace+0x0/0x340 show_stack+0x18/0x24 dump_stack_lvl+0x9c/0xbc print_address_description.constprop.0+0x74/0x2b0 kasan_report+0x1d8/0x1f0 kasan_check_range+0xf8/0x1a0 memcpy+0x84/0xf4 ubifs_tnc_end_commit+0xa5c/0x1950 do_commit+0x4e0/0x1340 ubifs_bg_thread+0x234/0x2e0 kthread+0x36c/0x410 ret_from_fork+0x10/0x20 Allocated by task 401: kasan_save_stack+0x38/0x70 __kasan_kmalloc+0x8c/0xd0 __kmalloc+0x34c/0x5bc tnc_insert+0x140/0x16a4 ubifs_tnc_add+0x370/0x52c ubifs_jnl_write_data+0x5d8/0x870 do_writepage+0x36c/0x510 ubifs_writepage+0x190/0x4dc __writepage+0x58/0x154 write_cache_pages+0x394/0x830 do_writepages+0x1f0/0x5b0 filemap_fdatawrite_wbc+0x170/0x25c file_write_and_wait_range+0x140/0x190 ubifs_fsync+0xe8/0x290 vfs_fsync_range+0xc0/0x1e4 do_fsync+0x40/0x90 __arm64_sys_fsync+0x34/0x50 invoke_syscall.constprop.0+0xa8/0x260 do_el0_svc+0xc8/0x1f0 el0_svc+0x34/0x70 el0t_64_sync_handler+0x108/0x114 el0t_64_sync+0x1a4/0x1a8 Freed by task 403: kasan_save_stack+0x38/0x70 kasan_set_track+0x28/0x40 kasan_set_free_info+0x28/0x4c __kasan_slab_free+0xd4/0x13c kfree+0xc4/0x3a0 tnc_delete+0x3f4/0xe40 ubifs_tnc_remove_range+0x368/0x73c ubifs_tnc_remove_ino+0x29c/0x2e0 ubifs_jnl_delete_inode+0x150/0x260 ubifs_evict_inode+0x1d4/0x2e4 evict+0x1c8/0x450 iput+0x2a0/0x3c4 do_unlinkat+0x2cc/0x490 __arm64_sys_unlinkat+0x90/0x100 invoke_syscall.constprop.0+0xa8/0x260 do_el0_svc+0xc8/0x1f0 el0_svc+0x34/0x70 el0t_64_sync_handler+0x108/0x114 el0t_64_sync+0x1a4/0x1a8 The offending `memcpy()` in `ubifs_copy_hash()` has a use-after-free when a node becomes root in TNC but still has a `cparent` to an already freed node. More specifically, consider the following TNC: zroot / / zp1 / / zn Inserting a new node `zn_new` with a key smaller then `zn` will trigger a split in `tnc_insert()` if `zp1` is full: zroot / \ / \ zp1 zp2 / \ / \ zn_new zn `zn->parent` has now been moved to `zp2`, *but* `zn->cparent` still points to `zp1`. Now, consider a removal of all the nodes _except_ `zn`. Just when `tnc_delete()` is about to delete `zroot` and `zp2`: zroot \ \ zp2 \ \ zn `zroot` and `zp2` get freed and the tree collapses: zn `zn` now becomes the new `zroot`. `get_znodes_to_commit()` will now only find `zn`, the new `zroot`, and `write_index()` will check its `znode->cparent` that wrongly points to the already freed `zp1`. `ubifs_copy_hash()` thus gets wrongly called with `znode->cparent->zbranch[znode->iip].hash` that triggers the use-after-free! Fix this by explicitly setting `znode->cparent` to `NULL` in `get_znodes_to_commit()` for the root node. The search for the dirty nodes ---truncated---

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix race in concurrent f2fs_stop_gc_thread In my test case, concurrent calls to f2fs shutdown report the following stack trace: Oops: general protection fault, probably for non-canonical address 0xc6cfff63bb5513fc: 0000 [#1] PREEMPT SMP PTI CPU: 0 UID: 0 PID: 678 Comm: f2fs_rep_shutdo Not tainted 6.12.0-rc5-next-20241029-g6fb2fa9805c5-dirty #85 Call Trace: <TASK> ? show_regs+0x8b/0xa0 ? __die_body+0x26/0xa0 ? die_addr+0x54/0x90 ? exc_general_protection+0x24b/0x5c0 ? asm_exc_general_protection+0x26/0x30 ? kthread_stop+0x46/0x390 f2fs_stop_gc_thread+0x6c/0x110 f2fs_do_shutdown+0x309/0x3a0 f2fs_ioc_shutdown+0x150/0x1c0 __f2fs_ioctl+0xffd/0x2ac0 f2fs_ioctl+0x76/0xe0 vfs_ioctl+0x23/0x60 __x64_sys_ioctl+0xce/0xf0 x64_sys_call+0x2b1b/0x4540 do_syscall_64+0xa7/0x240 entry_SYSCALL_64_after_hwframe+0x76/0x7e The root cause is a race condition in f2fs_stop_gc_thread() called from different f2fs shutdown paths: [CPU0] [CPU1] ---------------------- ----------------------- f2fs_stop_gc_thread f2fs_stop_gc_thread gc_th = sbi->gc_thread gc_th = sbi->gc_thread kfree(gc_th) sbi->gc_thread = NULL < gc_th != NULL > kthread_stop(gc_th->f2fs_gc_task) //UAF The commit c7f114d864ac ("f2fs: fix to avoid use-after-free in f2fs_stop_gc_thread()") attempted to fix this issue by using a read semaphore to prevent races between shutdown and remount threads, but it fails to prevent all race conditions. Fix it by converting to write lock of s_umount in f2fs_do_shutdown().

In the Linux kernel, the following vulnerability has been resolved: fsnotify: Fix ordering of iput() and watched_objects decrement Ensure the superblock is kept alive until we're done with iput(). Holding a reference to an inode is not allowed unless we ensure the superblock stays alive, which fsnotify does by keeping the watched_objects count elevated, so iput() must happen before the watched_objects decrement. This can lead to a UAF of something like sb->s_fs_info in tmpfs, but the UAF is hard to hit because race orderings that oops are more likely, thanks to the CHECK_DATA_CORRUPTION() block in generic_shutdown_super(). Also, ensure that fsnotify_put_sb_watched_objects() doesn't call fsnotify_sb_watched_objects() on a superblock that may have already been freed, which would cause a UAF read of sb->s_fsnotify_info.

Memory corruption may occur while accessing a variable during extended back to back tests.

In the Linux kernel, the following vulnerability has been resolved: scsi: iscsi: Fix iscsi_task use after free Commit d39df158518c ("scsi: iscsi: Have abort handler get ref to conn") added iscsi_get_conn()/iscsi_put_conn() calls during abort handling but then also changed the handling of the case where we detect an already completed task where we now end up doing a goto to the common put/cleanup code. This results in a iscsi_task use after free, because the common cleanup code will do a put on the iscsi_task. This reverts the goto and moves the iscsi_get_conn() to after we've checked if the iscsi_task is valid.

In the Linux kernel, the following vulnerability has been resolved: sctp: fix possible UAF in sctp_v6_available() A lockdep report [1] with CONFIG_PROVE_RCU_LIST=y hints that sctp_v6_available() is calling dev_get_by_index_rcu() and ipv6_chk_addr() without holding rcu. [1] ============================= WARNING: suspicious RCU usage 6.12.0-rc5-virtme #1216 Tainted: G W ----------------------------- net/core/dev.c:876 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by sctp_hello/31495: #0: ffff9f1ebbdb7418 (sk_lock-AF_INET6){+.+.}-{0:0}, at: sctp_bind (./arch/x86/include/asm/jump_label.h:27 net/sctp/socket.c:315) sctp stack backtrace: CPU: 7 UID: 0 PID: 31495 Comm: sctp_hello Tainted: G W 6.12.0-rc5-virtme #1216 Tainted: [W]=WARN Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:123) lockdep_rcu_suspicious (kernel/locking/lockdep.c:6822) dev_get_by_index_rcu (net/core/dev.c:876 (discriminator 7)) sctp_v6_available (net/sctp/ipv6.c:701) sctp sctp_do_bind (net/sctp/socket.c:400 (discriminator 1)) sctp sctp_bind (net/sctp/socket.c:320) sctp inet6_bind_sk (net/ipv6/af_inet6.c:465) ? security_socket_bind (security/security.c:4581 (discriminator 1)) __sys_bind (net/socket.c:1848 net/socket.c:1869) ? do_user_addr_fault (./include/linux/rcupdate.h:347 ./include/linux/rcupdate.h:880 ./include/linux/mm.h:729 arch/x86/mm/fault.c:1340) ? do_user_addr_fault (./arch/x86/include/asm/preempt.h:84 (discriminator 13) ./include/linux/rcupdate.h:98 (discriminator 13) ./include/linux/rcupdate.h:882 (discriminator 13) ./include/linux/mm.h:729 (discriminator 13) arch/x86/mm/fault.c:1340 (discriminator 13)) __x64_sys_bind (net/socket.c:1877 (discriminator 1) net/socket.c:1875 (discriminator 1) net/socket.c:1875 (discriminator 1)) do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) RIP: 0033:0x7f59b934a1e7 Code: 44 00 00 48 8b 15 39 8c 0c 00 f7 d8 64 89 02 b8 ff ff ff ff eb bd 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 b8 31 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 09 8c 0c 00 f7 d8 64 89 01 48 All code ======== 0: 44 00 00 add %r8b,(%rax) 3: 48 8b 15 39 8c 0c 00 mov 0xc8c39(%rip),%rdx # 0xc8c43 a: f7 d8 neg %eax c: 64 89 02 mov %eax,%fs:(%rdx) f: b8 ff ff ff ff mov $0xffffffff,%eax 14: eb bd jmp 0xffffffffffffffd3 16: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 1d: 00 00 00 20: 0f 1f 00 nopl (%rax) 23: b8 31 00 00 00 mov $0x31,%eax 28: 0f 05 syscall 2a:* 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 30: 73 01 jae 0x33 32: c3 ret 33: 48 8b 0d 09 8c 0c 00 mov 0xc8c09(%rip),%rcx # 0xc8c43 3a: f7 d8 neg %eax 3c: 64 89 01 mov %eax,%fs:(%rcx) 3f: 48 rex.W Code starting with the faulting instruction =========================================== 0: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax 6: 73 01 jae 0x9 8: c3 ret 9: 48 8b 0d 09 8c 0c 00 mov 0xc8c09(%rip),%rcx # 0xc8c19 10: f7 d8 neg %eax 12: 64 89 01 mov %eax,%fs:(%rcx) 15: 48 rex.W RSP: 002b:00007ffe2d0ad398 EFLAGS: 00000202 ORIG_RAX: 0000000000000031 RAX: ffffffffffffffda RBX: 00007ffe2d0ad3d0 RCX: 00007f59b934a1e7 RDX: 000000000000001c RSI: 00007ffe2d0ad3d0 RDI: 0000000000000005 RBP: 0000000000000005 R08: 1999999999999999 R09: 0000000000000000 R10: 00007f59b9253298 R11: 000000000000 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: ALSA: 6fire: Release resources at card release The current 6fire code tries to release the resources right after the call of usb6fire_chip_abort(). But at this moment, the card object might be still in use (as we're calling snd_card_free_when_closed()). For avoid potential UAFs, move the release of resources to the card's private_free instead of the manual call of usb6fire_chip_destroy() at the USB disconnect callback.

In the Linux kernel, the following vulnerability has been resolved: smb: prevent use-after-free due to open_cached_dir error paths If open_cached_dir() encounters an error parsing the lease from the server, the error handling may race with receiving a lease break, resulting in open_cached_dir() freeing the cfid while the queued work is pending. Update open_cached_dir() to drop refs rather than directly freeing the cfid. Have cached_dir_lease_break(), cfids_laundromat_worker(), and invalidate_all_cached_dirs() clear has_lease immediately while still holding cfids->cfid_list_lock, and then use this to also simplify the reference counting in cfids_laundromat_worker() and invalidate_all_cached_dirs(). Fixes this KASAN splat (which manually injects an error and lease break in open_cached_dir()): ================================================================== BUG: KASAN: slab-use-after-free in smb2_cached_lease_break+0x27/0xb0 Read of size 8 at addr ffff88811cc24c10 by task kworker/3:1/65 CPU: 3 UID: 0 PID: 65 Comm: kworker/3:1 Not tainted 6.12.0-rc6-g255cf264e6e5-dirty #87 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020 Workqueue: cifsiod smb2_cached_lease_break Call Trace: <TASK> dump_stack_lvl+0x77/0xb0 print_report+0xce/0x660 kasan_report+0xd3/0x110 smb2_cached_lease_break+0x27/0xb0 process_one_work+0x50a/0xc50 worker_thread+0x2ba/0x530 kthread+0x17c/0x1c0 ret_from_fork+0x34/0x60 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 2464: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 __kasan_kmalloc+0xaa/0xb0 open_cached_dir+0xa7d/0x1fb0 smb2_query_path_info+0x43c/0x6e0 cifs_get_fattr+0x346/0xf10 cifs_get_inode_info+0x157/0x210 cifs_revalidate_dentry_attr+0x2d1/0x460 cifs_getattr+0x173/0x470 vfs_statx_path+0x10f/0x160 vfs_statx+0xe9/0x150 vfs_fstatat+0x5e/0xc0 __do_sys_newfstatat+0x91/0xf0 do_syscall_64+0x95/0x1a0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Freed by task 2464: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x51/0x70 kfree+0x174/0x520 open_cached_dir+0x97f/0x1fb0 smb2_query_path_info+0x43c/0x6e0 cifs_get_fattr+0x346/0xf10 cifs_get_inode_info+0x157/0x210 cifs_revalidate_dentry_attr+0x2d1/0x460 cifs_getattr+0x173/0x470 vfs_statx_path+0x10f/0x160 vfs_statx+0xe9/0x150 vfs_fstatat+0x5e/0xc0 __do_sys_newfstatat+0x91/0xf0 do_syscall_64+0x95/0x1a0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Last potentially related work creation: kasan_save_stack+0x33/0x60 __kasan_record_aux_stack+0xad/0xc0 insert_work+0x32/0x100 __queue_work+0x5c9/0x870 queue_work_on+0x82/0x90 open_cached_dir+0x1369/0x1fb0 smb2_query_path_info+0x43c/0x6e0 cifs_get_fattr+0x346/0xf10 cifs_get_inode_info+0x157/0x210 cifs_revalidate_dentry_attr+0x2d1/0x460 cifs_getattr+0x173/0x470 vfs_statx_path+0x10f/0x160 vfs_statx+0xe9/0x150 vfs_fstatat+0x5e/0xc0 __do_sys_newfstatat+0x91/0xf0 do_syscall_64+0x95/0x1a0 entry_SYSCALL_64_after_hwframe+0x76/0x7e The buggy address belongs to the object at ffff88811cc24c00 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 16 bytes inside of freed 1024-byte region [ffff88811cc24c00, ffff88811cc25000)

In the Linux kernel, the following vulnerability has been resolved: i40e: Fix use-after-free in i40e_client_subtask() Currently the call to i40e_client_del_instance frees the object pf->cinst, however pf->cinst->lan_info is being accessed after the free. Fix this by adding the missing return. Addresses-Coverity: ("Read from pointer after free")

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-use-after-free in smb3_preauth_hash_rsp ksmbd_user_session_put should be called under smb3_preauth_hash_rsp(). It will avoid freeing session before calling smb3_preauth_hash_rsp().

In the Linux kernel, the following vulnerability has been resolved: netfilter: Fix use-after-free in get_info() ip6table_nat module unload has refcnt warning for UAF. call trace is: WARNING: CPU: 1 PID: 379 at kernel/module/main.c:853 module_put+0x6f/0x80 Modules linked in: ip6table_nat(-) CPU: 1 UID: 0 PID: 379 Comm: ip6tables Not tainted 6.12.0-rc4-00047-gc2ee9f594da8-dirty #205 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 RIP: 0010:module_put+0x6f/0x80 Call Trace: <TASK> get_info+0x128/0x180 do_ip6t_get_ctl+0x6a/0x430 nf_getsockopt+0x46/0x80 ipv6_getsockopt+0xb9/0x100 rawv6_getsockopt+0x42/0x190 do_sock_getsockopt+0xaa/0x180 __sys_getsockopt+0x70/0xc0 __x64_sys_getsockopt+0x20/0x30 do_syscall_64+0xa2/0x1a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Concurrent execution of module unload and get_info() trigered the warning. The root cause is as follows: cpu0 cpu1 module_exit //mod->state = MODULE_STATE_GOING ip6table_nat_exit xt_unregister_template kfree(t) //removed from templ_list getinfo() t = xt_find_table_lock list_for_each_entry(tmpl, &xt_templates[af]...) if (strcmp(tmpl->name, name)) continue; //table not found try_module_get list_for_each_entry(t, &xt_net->tables[af]...) return t; //not get refcnt module_put(t->me) //uaf unregister_pernet_subsys //remove table from xt_net list While xt_table module was going away and has been removed from xt_templates list, we couldnt get refcnt of xt_table->me. Check module in xt_net->tables list re-traversal to fix it.

In the Linux kernel, the following vulnerability has been resolved: net: sched: use RCU read-side critical section in taprio_dump() Fix possible use-after-free in 'taprio_dump()' by adding RCU read-side critical section there. Never seen on x86 but found on a KASAN-enabled arm64 system when investigating https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa: [T15862] BUG: KASAN: slab-use-after-free in taprio_dump+0xa0c/0xbb0 [T15862] Read of size 4 at addr ffff0000d4bb88f8 by task repro/15862 [T15862] [T15862] CPU: 0 UID: 0 PID: 15862 Comm: repro Not tainted 6.11.0-rc1-00293-gdefaf1a2113a-dirty #2 [T15862] Hardware name: QEMU QEMU Virtual Machine, BIOS edk2-20240524-5.fc40 05/24/2024 [T15862] Call trace: [T15862] dump_backtrace+0x20c/0x220 [T15862] show_stack+0x2c/0x40 [T15862] dump_stack_lvl+0xf8/0x174 [T15862] print_report+0x170/0x4d8 [T15862] kasan_report+0xb8/0x1d4 [T15862] __asan_report_load4_noabort+0x20/0x2c [T15862] taprio_dump+0xa0c/0xbb0 [T15862] tc_fill_qdisc+0x540/0x1020 [T15862] qdisc_notify.isra.0+0x330/0x3a0 [T15862] tc_modify_qdisc+0x7b8/0x1838 [T15862] rtnetlink_rcv_msg+0x3c8/0xc20 [T15862] netlink_rcv_skb+0x1f8/0x3d4 [T15862] rtnetlink_rcv+0x28/0x40 [T15862] netlink_unicast+0x51c/0x790 [T15862] netlink_sendmsg+0x79c/0xc20 [T15862] __sock_sendmsg+0xe0/0x1a0 [T15862] ____sys_sendmsg+0x6c0/0x840 [T15862] ___sys_sendmsg+0x1ac/0x1f0 [T15862] __sys_sendmsg+0x110/0x1d0 [T15862] __arm64_sys_sendmsg+0x74/0xb0 [T15862] invoke_syscall+0x88/0x2e0 [T15862] el0_svc_common.constprop.0+0xe4/0x2a0 [T15862] do_el0_svc+0x44/0x60 [T15862] el0_svc+0x50/0x184 [T15862] el0t_64_sync_handler+0x120/0x12c [T15862] el0t_64_sync+0x190/0x194 [T15862] [T15862] Allocated by task 15857: [T15862] kasan_save_stack+0x3c/0x70 [T15862] kasan_save_track+0x20/0x3c [T15862] kasan_save_alloc_info+0x40/0x60 [T15862] __kasan_kmalloc+0xd4/0xe0 [T15862] __kmalloc_cache_noprof+0x194/0x334 [T15862] taprio_change+0x45c/0x2fe0 [T15862] tc_modify_qdisc+0x6a8/0x1838 [T15862] rtnetlink_rcv_msg+0x3c8/0xc20 [T15862] netlink_rcv_skb+0x1f8/0x3d4 [T15862] rtnetlink_rcv+0x28/0x40 [T15862] netlink_unicast+0x51c/0x790 [T15862] netlink_sendmsg+0x79c/0xc20 [T15862] __sock_sendmsg+0xe0/0x1a0 [T15862] ____sys_sendmsg+0x6c0/0x840 [T15862] ___sys_sendmsg+0x1ac/0x1f0 [T15862] __sys_sendmsg+0x110/0x1d0 [T15862] __arm64_sys_sendmsg+0x74/0xb0 [T15862] invoke_syscall+0x88/0x2e0 [T15862] el0_svc_common.constprop.0+0xe4/0x2a0 [T15862] do_el0_svc+0x44/0x60 [T15862] el0_svc+0x50/0x184 [T15862] el0t_64_sync_handler+0x120/0x12c [T15862] el0t_64_sync+0x190/0x194 [T15862] [T15862] Freed by task 6192: [T15862] kasan_save_stack+0x3c/0x70 [T15862] kasan_save_track+0x20/0x3c [T15862] kasan_save_free_info+0x4c/0x80 [T15862] poison_slab_object+0x110/0x160 [T15862] __kasan_slab_free+0x3c/0x74 [T15862] kfree+0x134/0x3c0 [T15862] taprio_free_sched_cb+0x18c/0x220 [T15862] rcu_core+0x920/0x1b7c [T15862] rcu_core_si+0x10/0x1c [T15862] handle_softirqs+0x2e8/0xd64 [T15862] __do_softirq+0x14/0x20

In the Linux kernel, the following vulnerability has been resolved: block, bfq: fix uaf for accessing waker_bfqq after splitting After commit 42c306ed7233 ("block, bfq: don't break merge chain in bfq_split_bfqq()"), if the current procress is the last holder of bfqq, the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq may in the merge chain of bfqq, hence just recored waker_bfqq is still not safe. Fix the problem by adding a helper bfq_waker_bfqq() to check if bfqq->waker_bfqq is in the merge chain, and current procress is the only holder.

In the Linux kernel, the following vulnerability has been resolved: spi: mpc52xx: Add cancel_work_sync before module remove If we remove the module which will call mpc52xx_spi_remove it will free 'ms' through spi_unregister_controller. while the work ms->work will be used. The sequence of operations that may lead to a UAF bug. Fix it by ensuring that the work is canceled before proceeding with the cleanup in mpc52xx_spi_remove.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix slab-use-after-free in ksmbd_smb2_session_create There is a race condition between ksmbd_smb2_session_create and ksmbd_expire_session. This patch add missing sessions_table_lock while adding/deleting session from global session table.

In the Linux kernel, the following vulnerability has been resolved: ext4: avoid use-after-free in ext4_ext_show_leaf() In ext4_find_extent(), path may be freed by error or be reallocated, so using a previously saved *ppath may have been freed and thus may trigger use-after-free, as follows: ext4_split_extent path = *ppath; ext4_split_extent_at(ppath) path = ext4_find_extent(ppath) ext4_split_extent_at(ppath) // ext4_find_extent fails to free path // but zeroout succeeds ext4_ext_show_leaf(inode, path) eh = path[depth].p_hdr // path use-after-free !!! Similar to ext4_split_extent_at(), we use *ppath directly as an input to ext4_ext_show_leaf(). Fix a spelling error by the way. Same problem in ext4_ext_handle_unwritten_extents(). Since 'path' is only used in ext4_ext_show_leaf(), remove 'path' and use *ppath directly. This issue is triggered only when EXT_DEBUG is defined and therefore does not affect functionality.

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix user-after-free from session log off There is racy issue between smb2 session log off and smb2 session setup. It will cause user-after-free from session log off. This add session_lock when setting SMB2_SESSION_EXPIRED and referece count to session struct not to free session while it is being used.

In the Linux kernel, the following vulnerability has been resolved: uprobe: avoid out-of-bounds memory access of fetching args Uprobe needs to fetch args into a percpu buffer, and then copy to ring buffer to avoid non-atomic context problem. Sometimes user-space strings, arrays can be very large, but the size of percpu buffer is only page size. And store_trace_args() won't check whether these data exceeds a single page or not, caused out-of-bounds memory access. It could be reproduced by following steps: 1. build kernel with CONFIG_KASAN enabled 2. save follow program as test.c ``` \#include <stdio.h> \#include <stdlib.h> \#include <string.h> // If string length large than MAX_STRING_SIZE, the fetch_store_strlen() // will return 0, cause __get_data_size() return shorter size, and // store_trace_args() will not trigger out-of-bounds access. // So make string length less than 4096. \#define STRLEN 4093 void generate_string(char *str, int n) { int i; for (i = 0; i < n; ++i) { char c = i % 26 + 'a'; str[i] = c; } str[n-1] = '\0'; } void print_string(char *str) { printf("%s\n", str); } int main() { char tmp[STRLEN]; generate_string(tmp, STRLEN); print_string(tmp); return 0; } ``` 3. compile program `gcc -o test test.c` 4. get the offset of `print_string()` ``` objdump -t test | grep -w print_string 0000000000401199 g F .text 000000000000001b print_string ``` 5. configure uprobe with offset 0x1199 ``` off=0x1199 cd /sys/kernel/debug/tracing/ echo "p /root/test:${off} arg1=+0(%di):ustring arg2=\$comm arg3=+0(%di):ustring" > uprobe_events echo 1 > events/uprobes/enable echo 1 > tracing_on ``` 6. run `test`, and kasan will report error. ================================================================== BUG: KASAN: use-after-free in strncpy_from_user+0x1d6/0x1f0 Write of size 8 at addr ffff88812311c004 by task test/499CPU: 0 UID: 0 PID: 499 Comm: test Not tainted 6.12.0-rc3+ #18 Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x55/0x70 print_address_description.constprop.0+0x27/0x310 kasan_report+0x10f/0x120 ? strncpy_from_user+0x1d6/0x1f0 strncpy_from_user+0x1d6/0x1f0 ? rmqueue.constprop.0+0x70d/0x2ad0 process_fetch_insn+0xb26/0x1470 ? __pfx_process_fetch_insn+0x10/0x10 ? _raw_spin_lock+0x85/0xe0 ? __pfx__raw_spin_lock+0x10/0x10 ? __pte_offset_map+0x1f/0x2d0 ? unwind_next_frame+0xc5f/0x1f80 ? arch_stack_walk+0x68/0xf0 ? is_bpf_text_address+0x23/0x30 ? kernel_text_address.part.0+0xbb/0xd0 ? __kernel_text_address+0x66/0xb0 ? unwind_get_return_address+0x5e/0xa0 ? __pfx_stack_trace_consume_entry+0x10/0x10 ? arch_stack_walk+0xa2/0xf0 ? _raw_spin_lock_irqsave+0x8b/0xf0 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 ? depot_alloc_stack+0x4c/0x1f0 ? _raw_spin_unlock_irqrestore+0xe/0x30 ? stack_depot_save_flags+0x35d/0x4f0 ? kasan_save_stack+0x34/0x50 ? kasan_save_stack+0x24/0x50 ? mutex_lock+0x91/0xe0 ? __pfx_mutex_lock+0x10/0x10 prepare_uprobe_buffer.part.0+0x2cd/0x500 uprobe_dispatcher+0x2c3/0x6a0 ? __pfx_uprobe_dispatcher+0x10/0x10 ? __kasan_slab_alloc+0x4d/0x90 handler_chain+0xdd/0x3e0 handle_swbp+0x26e/0x3d0 ? __pfx_handle_swbp+0x10/0x10 ? uprobe_pre_sstep_notifier+0x151/0x1b0 irqentry_exit_to_user_mode+0xe2/0x1b0 asm_exc_int3+0x39/0x40 RIP: 0033:0x401199 Code: 01 c2 0f b6 45 fb 88 02 83 45 fc 01 8b 45 fc 3b 45 e4 7c b7 8b 45 e4 48 98 48 8d 50 ff 48 8b 45 e8 48 01 d0 ce RSP: 002b:00007ffdf00576a8 EFLAGS: 00000206 RAX: 00007ffdf00576b0 RBX: 0000000000000000 RCX: 0000000000000ff2 RDX: 0000000000000ffc RSI: 0000000000000ffd RDI: 00007ffdf00576b0 RBP: 00007ffdf00586b0 R08: 00007feb2f9c0d20 R09: 00007feb2f9c0d20 R10: 0000000000000001 R11: 0000000000000202 R12: 0000000000401040 R13: 00007ffdf0058780 R14: 0000000000000000 R15: 0000000000000000 </TASK> This commit enforces the buffer's maxlen less than a page-size to avoid store_trace_args() out-of-memory access.

In the Linux kernel, the following vulnerability has been resolved: net/xen-netback: prevent UAF in xenvif_flush_hash() During the list_for_each_entry_rcu iteration call of xenvif_flush_hash, kfree_rcu does not exist inside the rcu read critical section, so if kfree_rcu is called when the rcu grace period ends during the iteration, UAF occurs when accessing head->next after the entry becomes free. Therefore, to solve this, you need to change it to list_for_each_entry_safe.

In the Linux kernel, the following vulnerability has been resolved: fbdev: pxafb: Fix possible use after free in pxafb_task() In the pxafb_probe function, it calls the pxafb_init_fbinfo function, after which &fbi->task is associated with pxafb_task. Moreover, within this pxafb_init_fbinfo function, the pxafb_blank function within the &pxafb_ops struct is capable of scheduling work. If we remove the module which will call pxafb_remove to make cleanup, it will call unregister_framebuffer function which can call do_unregister_framebuffer to free fbi->fb through put_fb_info(fb_info), while the work mentioned above will be used. The sequence of operations that may lead to a UAF bug is as follows: CPU0 CPU1 | pxafb_task pxafb_remove | unregister_framebuffer(info) | do_unregister_framebuffer(fb_info) | put_fb_info(fb_info) | // free fbi->fb | set_ctrlr_state(fbi, state) | __pxafb_lcd_power(fbi, 0) | fbi->lcd_power(on, &fbi->fb.var) | //use fbi->fb Fix it by ensuring that the work is canceled before proceeding with the cleanup in pxafb_remove. Note that only root user can remove the driver at runtime.

In the Linux kernel, the following vulnerability has been resolved: drm/xe/tracing: Fix a potential TP_printk UAF The commit afd2627f727b ("tracing: Check "%s" dereference via the field and not the TP_printk format") exposes potential UAFs in the xe_bo_move trace event. Fix those by avoiding dereferencing the xe_mem_type_to_name[] array at TP_printk time. Since some code refactoring has taken place, explicit backporting may be needed for kernels older than 6.10.

In the Linux kernel, the following vulnerability has been resolved: aoe: fix the potential use-after-free problem in more places For fixing CVE-2023-6270, f98364e92662 ("aoe: fix the potential use-after-free problem in aoecmd_cfg_pkts") makes tx() calling dev_put() instead of doing in aoecmd_cfg_pkts(). It avoids that the tx() runs into use-after-free. Then Nicolai Stange found more places in aoe have potential use-after-free problem with tx(). e.g. revalidate(), aoecmd_ata_rw(), resend(), probe() and aoecmd_cfg_rsp(). Those functions also use aoenet_xmit() to push packet to tx queue. So they should also use dev_hold() to increase the refcnt of skb->dev. On the other hand, moving dev_put() to tx() causes that the refcnt of skb->dev be reduced to a negative value, because corresponding dev_hold() are not called in revalidate(), aoecmd_ata_rw(), resend(), probe(), and aoecmd_cfg_rsp(). This patch fixed this issue.

In the Linux kernel, the following vulnerability has been resolved: ext4: fix timer use-after-free on failed mount Syzbot has found an ODEBUG bug in ext4_fill_super The del_timer_sync function cancels the s_err_report timer, which reminds about filesystem errors daily. We should guarantee the timer is no longer active before kfree(sbi). When filesystem mounting fails, the flow goes to failed_mount3, where an error occurs when ext4_stop_mmpd is called, causing a read I/O failure. This triggers the ext4_handle_error function that ultimately re-arms the timer, leaving the s_err_report timer active before kfree(sbi) is called. Fix the issue by canceling the s_err_report timer after calling ext4_stop_mmpd.

In the Linux kernel, the following vulnerability has been resolved: vsock/virtio: Initialization of the dangling pointer occurring in vsk->trans During loopback communication, a dangling pointer can be created in vsk->trans, potentially leading to a Use-After-Free condition. This issue is resolved by initializing vsk->trans to NULL.

In the Linux kernel, the following vulnerability has been resolved: netfilter: bpf: must hold reference on net namespace BUG: KASAN: slab-use-after-free in __nf_unregister_net_hook+0x640/0x6b0 Read of size 8 at addr ffff8880106fe400 by task repro/72= bpf_nf_link_release+0xda/0x1e0 bpf_link_free+0x139/0x2d0 bpf_link_release+0x68/0x80 __fput+0x414/0xb60 Eric says: It seems that bpf was able to defer the __nf_unregister_net_hook() after exit()/close() time. Perhaps a netns reference is missing, because the netns has been dismantled/freed already. bpf_nf_link_attach() does : link->net = net; But I do not see a reference being taken on net. Add such a reference and release it after hook unreg. Note that I was unable to get syzbot reproducer to work, so I do not know if this resolves this splat.

In the Linux kernel, the following vulnerability has been resolved: net: ti: fix UAF in tlan_remove_one priv is netdev private data and it cannot be used after free_netdev() call. Using priv after free_netdev() can cause UAF bug. Fix it by moving free_netdev() at the end of the function.

In the Linux kernel, the following vulnerability has been resolved: macsec: Fix use-after-free while sending the offloading packet KASAN reports the following UAF. The metadata_dst, which is used to store the SCI value for macsec offload, is already freed by metadata_dst_free() in macsec_free_netdev(), while driver still use it for sending the packet. To fix this issue, dst_release() is used instead to release metadata_dst. So it is not freed instantly in macsec_free_netdev() if still referenced by skb. BUG: KASAN: slab-use-after-free in mlx5e_xmit+0x1e8f/0x4190 [mlx5_core] Read of size 2 at addr ffff88813e42e038 by task kworker/7:2/714 [...] Workqueue: mld mld_ifc_work Call Trace: <TASK> dump_stack_lvl+0x51/0x60 print_report+0xc1/0x600 kasan_report+0xab/0xe0 mlx5e_xmit+0x1e8f/0x4190 [mlx5_core] dev_hard_start_xmit+0x120/0x530 sch_direct_xmit+0x149/0x11e0 __qdisc_run+0x3ad/0x1730 __dev_queue_xmit+0x1196/0x2ed0 vlan_dev_hard_start_xmit+0x32e/0x510 [8021q] dev_hard_start_xmit+0x120/0x530 __dev_queue_xmit+0x14a7/0x2ed0 macsec_start_xmit+0x13e9/0x2340 dev_hard_start_xmit+0x120/0x530 __dev_queue_xmit+0x14a7/0x2ed0 ip6_finish_output2+0x923/0x1a70 ip6_finish_output+0x2d7/0x970 ip6_output+0x1ce/0x3a0 NF_HOOK.constprop.0+0x15f/0x190 mld_sendpack+0x59a/0xbd0 mld_ifc_work+0x48a/0xa80 process_one_work+0x5aa/0xe50 worker_thread+0x79c/0x1290 kthread+0x28f/0x350 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x11/0x20 </TASK> Allocated by task 3922: kasan_save_stack+0x20/0x40 kasan_save_track+0x10/0x30 __kasan_kmalloc+0x77/0x90 __kmalloc_noprof+0x188/0x400 metadata_dst_alloc+0x1f/0x4e0 macsec_newlink+0x914/0x1410 __rtnl_newlink+0xe08/0x15b0 rtnl_newlink+0x5f/0x90 rtnetlink_rcv_msg+0x667/0xa80 netlink_rcv_skb+0x12c/0x360 netlink_unicast+0x551/0x770 netlink_sendmsg+0x72d/0xbd0 __sock_sendmsg+0xc5/0x190 ____sys_sendmsg+0x52e/0x6a0 ___sys_sendmsg+0xeb/0x170 __sys_sendmsg+0xb5/0x140 do_syscall_64+0x4c/0x100 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Freed by task 4011: kasan_save_stack+0x20/0x40 kasan_save_track+0x10/0x30 kasan_save_free_info+0x37/0x50 poison_slab_object+0x10c/0x190 __kasan_slab_free+0x11/0x30 kfree+0xe0/0x290 macsec_free_netdev+0x3f/0x140 netdev_run_todo+0x450/0xc70 rtnetlink_rcv_msg+0x66f/0xa80 netlink_rcv_skb+0x12c/0x360 netlink_unicast+0x551/0x770 netlink_sendmsg+0x72d/0xbd0 __sock_sendmsg+0xc5/0x190 ____sys_sendmsg+0x52e/0x6a0 ___sys_sendmsg+0xeb/0x170 __sys_sendmsg+0xb5/0x140 do_syscall_64+0x4c/0x100 entry_SYSCALL_64_after_hwframe+0x4b/0x53

In the Linux kernel, the following vulnerability has been resolved: net: sched: fix use-after-free in taprio_change() In 'taprio_change()', 'admin' pointer may become dangling due to sched switch / removal caused by 'advance_sched()', and critical section protected by 'q->current_entry_lock' is too small to prevent from such a scenario (which causes use-after-free detected by KASAN). Fix this by prefer 'rcu_replace_pointer()' over 'rcu_assign_pointer()' to update 'admin' immediately before an attempt to schedule freeing.

An issue was discovered in GNU Hurd before 0.9 20210404-9. libports accepts fake notification messages from any client on any port, which can lead to port use-after-free. This can be exploited for local privilege escalation to get full root access.

In the Linux kernel, the following vulnerability has been resolved: ext4: avoid OOB when system.data xattr changes underneath the filesystem When looking up for an entry in an inlined directory, if e_value_offs is changed underneath the filesystem by some change in the block device, it will lead to an out-of-bounds access that KASAN detects as an UAF. EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none. loop0: detected capacity change from 2048 to 2047 ================================================================== BUG: KASAN: use-after-free in ext4_search_dir+0xf2/0x1c0 fs/ext4/namei.c:1500 Read of size 1 at addr ffff88803e91130f by task syz-executor269/5103 CPU: 0 UID: 0 PID: 5103 Comm: syz-executor269 Not tainted 6.11.0-rc4-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 ext4_search_dir+0xf2/0x1c0 fs/ext4/namei.c:1500 ext4_find_inline_entry+0x4be/0x5e0 fs/ext4/inline.c:1697 __ext4_find_entry+0x2b4/0x1b30 fs/ext4/namei.c:1573 ext4_lookup_entry fs/ext4/namei.c:1727 [inline] ext4_lookup+0x15f/0x750 fs/ext4/namei.c:1795 lookup_one_qstr_excl+0x11f/0x260 fs/namei.c:1633 filename_create+0x297/0x540 fs/namei.c:3980 do_symlinkat+0xf9/0x3a0 fs/namei.c:4587 __do_sys_symlinkat fs/namei.c:4610 [inline] __se_sys_symlinkat fs/namei.c:4607 [inline] __x64_sys_symlinkat+0x95/0xb0 fs/namei.c:4607 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3e73ced469 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 21 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff4d40c258 EFLAGS: 00000246 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0032656c69662f2e RCX: 00007f3e73ced469 RDX: 0000000020000200 RSI: 00000000ffffff9c RDI: 00000000200001c0 RBP: 0000000000000000 R08: 00007fff4d40c290 R09: 00007fff4d40c290 R10: 0023706f6f6c2f76 R11: 0000000000000246 R12: 00007fff4d40c27c R13: 0000000000000003 R14: 431bde82d7b634db R15: 00007fff4d40c2b0 </TASK> Calling ext4_xattr_ibody_find right after reading the inode with ext4_get_inode_loc will lead to a check of the validity of the xattrs, avoiding this problem.

Software installed and run as a non-privileged user may conduct improper GPU system calls to trigger use-after-free kernel exceptions.

Software installed and run as a non-privileged user may conduct GPU system calls to read and write freed physical memory from the GPU.

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid use-after-free in f2fs_stop_gc_thread() syzbot reports a f2fs bug as below: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_report+0xe8/0x550 mm/kasan/report.c:491 kasan_report+0x143/0x180 mm/kasan/report.c:601 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline] __refcount_add include/linux/refcount.h:184 [inline] __refcount_inc include/linux/refcount.h:241 [inline] refcount_inc include/linux/refcount.h:258 [inline] get_task_struct include/linux/sched/task.h:118 [inline] kthread_stop+0xca/0x630 kernel/kthread.c:704 f2fs_stop_gc_thread+0x65/0xb0 fs/f2fs/gc.c:210 f2fs_do_shutdown+0x192/0x540 fs/f2fs/file.c:2283 f2fs_ioc_shutdown fs/f2fs/file.c:2325 [inline] __f2fs_ioctl+0x443a/0xbe60 fs/f2fs/file.c:4325 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The root cause is below race condition, it may cause use-after-free issue in sbi->gc_th pointer. - remount - f2fs_remount - f2fs_stop_gc_thread - kfree(gc_th) - f2fs_ioc_shutdown - f2fs_do_shutdown - f2fs_stop_gc_thread - kthread_stop(gc_th->f2fs_gc_task) : sbi->gc_thread = NULL; We will call f2fs_do_shutdown() in two paths: - for f2fs_ioc_shutdown() path, we should grab sb->s_umount semaphore for fixing. - for f2fs_shutdown() path, it's safe since caller has already grabbed sb->s_umount semaphore.

In the Linux kernel, the following vulnerability has been resolved: af_unix: Don't return OOB skb in manage_oob(). syzbot reported use-after-free in unix_stream_recv_urg(). [0] The scenario is 1. send(MSG_OOB) 2. recv(MSG_OOB) -> The consumed OOB remains in recv queue 3. send(MSG_OOB) 4. recv() -> manage_oob() returns the next skb of the consumed OOB -> This is also OOB, but unix_sk(sk)->oob_skb is not cleared 5. recv(MSG_OOB) -> unix_sk(sk)->oob_skb is used but already freed The recent commit 8594d9b85c07 ("af_unix: Don't call skb_get() for OOB skb.") uncovered the issue. If the OOB skb is consumed and the next skb is peeked in manage_oob(), we still need to check if the skb is OOB. Let's do so by falling back to the following checks in manage_oob() and add the test case in selftest. Note that we need to add a similar check for SIOCATMARK. [0]: BUG: KASAN: slab-use-after-free in unix_stream_read_actor+0xa6/0xb0 net/unix/af_unix.c:2959 Read of size 4 at addr ffff8880326abcc4 by task syz-executor178/5235 CPU: 0 UID: 0 PID: 5235 Comm: syz-executor178 Not tainted 6.11.0-rc5-syzkaller-00742-gfbdaffe41adc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 unix_stream_read_actor+0xa6/0xb0 net/unix/af_unix.c:2959 unix_stream_recv_urg+0x1df/0x320 net/unix/af_unix.c:2640 unix_stream_read_generic+0x2456/0x2520 net/unix/af_unix.c:2778 unix_stream_recvmsg+0x22b/0x2c0 net/unix/af_unix.c:2996 sock_recvmsg_nosec net/socket.c:1046 [inline] sock_recvmsg+0x22f/0x280 net/socket.c:1068 ____sys_recvmsg+0x1db/0x470 net/socket.c:2816 ___sys_recvmsg net/socket.c:2858 [inline] __sys_recvmsg+0x2f0/0x3e0 net/socket.c:2888 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5360d6b4e9 Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff29b3a458 EFLAGS: 00000246 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 00007fff29b3a638 RCX: 00007f5360d6b4e9 RDX: 0000000000002001 RSI: 0000000020000640 RDI: 0000000000000003 RBP: 00007f5360dde610 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fff29b3a628 R14: 0000000000000001 R15: 0000000000000001 </TASK> Allocated by task 5235: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:312 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:338 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3988 [inline] slab_alloc_node mm/slub.c:4037 [inline] kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4080 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:667 alloc_skb include/linux/skbuff.h:1320 [inline] alloc_skb_with_frags+0xc3/0x770 net/core/skbuff.c:6528 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2815 sock_alloc_send_skb include/net/sock.h:1778 [inline] queue_oob+0x108/0x680 net/unix/af_unix.c:2198 unix_stream_sendmsg+0xd24/0xf80 net/unix/af_unix.c:2351 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2597 ___sys_sendmsg net/socket.c:2651 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2680 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5235: kasan_save_stack mm/kasan/common.c:47 ---truncated---

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double put of @cfile in smb2_set_path_size() If smb2_compound_op() is called with a valid @cfile and returned -EINVAL, we need to call cifs_get_writable_path() before retrying it as the reference of @cfile was already dropped by previous call. This fixes the following KASAN splat when running fstests generic/013 against Windows Server 2022: CIFS: Attempting to mount //w22-fs0/scratch run fstests generic/013 at 2024-09-02 19:48:59 ================================================================== BUG: KASAN: slab-use-after-free in detach_if_pending+0xab/0x200 Write of size 8 at addr ffff88811f1a3730 by task kworker/3:2/176 CPU: 3 UID: 0 PID: 176 Comm: kworker/3:2 Not tainted 6.11.0-rc6 #2 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-2.fc40 04/01/2014 Workqueue: cifsoplockd cifs_oplock_break [cifs] Call Trace: <TASK> dump_stack_lvl+0x5d/0x80 ? detach_if_pending+0xab/0x200 print_report+0x156/0x4d9 ? detach_if_pending+0xab/0x200 ? __virt_addr_valid+0x145/0x300 ? __phys_addr+0x46/0x90 ? detach_if_pending+0xab/0x200 kasan_report+0xda/0x110 ? detach_if_pending+0xab/0x200 detach_if_pending+0xab/0x200 timer_delete+0x96/0xe0 ? __pfx_timer_delete+0x10/0x10 ? rcu_is_watching+0x20/0x50 try_to_grab_pending+0x46/0x3b0 __cancel_work+0x89/0x1b0 ? __pfx___cancel_work+0x10/0x10 ? kasan_save_track+0x14/0x30 cifs_close_deferred_file+0x110/0x2c0 [cifs] ? __pfx_cifs_close_deferred_file+0x10/0x10 [cifs] ? __pfx_down_read+0x10/0x10 cifs_oplock_break+0x4c1/0xa50 [cifs] ? __pfx_cifs_oplock_break+0x10/0x10 [cifs] ? lock_is_held_type+0x85/0xf0 ? mark_held_locks+0x1a/0x90 process_one_work+0x4c6/0x9f0 ? find_held_lock+0x8a/0xa0 ? __pfx_process_one_work+0x10/0x10 ? lock_acquired+0x220/0x550 ? __list_add_valid_or_report+0x37/0x100 worker_thread+0x2e4/0x570 ? __kthread_parkme+0xd1/0xf0 ? __pfx_worker_thread+0x10/0x10 kthread+0x17f/0x1c0 ? kthread+0xda/0x1c0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x60 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 1118: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 __kasan_kmalloc+0xaa/0xb0 cifs_new_fileinfo+0xc8/0x9d0 [cifs] cifs_atomic_open+0x467/0x770 [cifs] lookup_open.isra.0+0x665/0x8b0 path_openat+0x4c3/0x1380 do_filp_open+0x167/0x270 do_sys_openat2+0x129/0x160 __x64_sys_creat+0xad/0xe0 do_syscall_64+0xbb/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 83: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x70 poison_slab_object+0xe9/0x160 __kasan_slab_free+0x32/0x50 kfree+0xf2/0x300 process_one_work+0x4c6/0x9f0 worker_thread+0x2e4/0x570 kthread+0x17f/0x1c0 ret_from_fork+0x31/0x60 ret_from_fork_asm+0x1a/0x30 Last potentially related work creation: kasan_save_stack+0x30/0x50 __kasan_record_aux_stack+0xad/0xc0 insert_work+0x29/0xe0 __queue_work+0x5ea/0x760 queue_work_on+0x6d/0x90 _cifsFileInfo_put+0x3f6/0x770 [cifs] smb2_compound_op+0x911/0x3940 [cifs] smb2_set_path_size+0x228/0x270 [cifs] cifs_set_file_size+0x197/0x460 [cifs] cifs_setattr+0xd9c/0x14b0 [cifs] notify_change+0x4e3/0x740 do_truncate+0xfa/0x180 vfs_truncate+0x195/0x200 __x64_sys_truncate+0x109/0x150 do_syscall_64+0xbb/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f

In the Linux kernel, the following vulnerability has been resolved: net: sched: flower: protect fl_walk() with rcu Patch that refactored fl_walk() to use idr_for_each_entry_continue_ul() also removed rcu protection of individual filters which causes following use-after-free when filter is deleted concurrently. Fix fl_walk() to obtain rcu read lock while iterating and taking the filter reference and temporary release the lock while calling arg->fn() callback that can sleep. KASAN trace: [ 352.773640] ================================================================== [ 352.775041] BUG: KASAN: use-after-free in fl_walk+0x159/0x240 [cls_flower] [ 352.776304] Read of size 4 at addr ffff8881c8251480 by task tc/2987 [ 352.777862] CPU: 3 PID: 2987 Comm: tc Not tainted 5.15.0-rc2+ #2 [ 352.778980] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 352.781022] Call Trace: [ 352.781573] dump_stack_lvl+0x46/0x5a [ 352.782332] print_address_description.constprop.0+0x1f/0x140 [ 352.783400] ? fl_walk+0x159/0x240 [cls_flower] [ 352.784292] ? fl_walk+0x159/0x240 [cls_flower] [ 352.785138] kasan_report.cold+0x83/0xdf [ 352.785851] ? fl_walk+0x159/0x240 [cls_flower] [ 352.786587] kasan_check_range+0x145/0x1a0 [ 352.787337] fl_walk+0x159/0x240 [cls_flower] [ 352.788163] ? fl_put+0x10/0x10 [cls_flower] [ 352.789007] ? __mutex_unlock_slowpath.constprop.0+0x220/0x220 [ 352.790102] tcf_chain_dump+0x231/0x450 [ 352.790878] ? tcf_chain_tp_delete_empty+0x170/0x170 [ 352.791833] ? __might_sleep+0x2e/0xc0 [ 352.792594] ? tfilter_notify+0x170/0x170 [ 352.793400] ? __mutex_unlock_slowpath.constprop.0+0x220/0x220 [ 352.794477] tc_dump_tfilter+0x385/0x4b0 [ 352.795262] ? tc_new_tfilter+0x1180/0x1180 [ 352.796103] ? __mod_node_page_state+0x1f/0xc0 [ 352.796974] ? __build_skb_around+0x10e/0x130 [ 352.797826] netlink_dump+0x2c0/0x560 [ 352.798563] ? netlink_getsockopt+0x430/0x430 [ 352.799433] ? __mutex_unlock_slowpath.constprop.0+0x220/0x220 [ 352.800542] __netlink_dump_start+0x356/0x440 [ 352.801397] rtnetlink_rcv_msg+0x3ff/0x550 [ 352.802190] ? tc_new_tfilter+0x1180/0x1180 [ 352.802872] ? rtnl_calcit.isra.0+0x1f0/0x1f0 [ 352.803668] ? tc_new_tfilter+0x1180/0x1180 [ 352.804344] ? _copy_from_iter_nocache+0x800/0x800 [ 352.805202] ? kasan_set_track+0x1c/0x30 [ 352.805900] netlink_rcv_skb+0xc6/0x1f0 [ 352.806587] ? rht_deferred_worker+0x6b0/0x6b0 [ 352.807455] ? rtnl_calcit.isra.0+0x1f0/0x1f0 [ 352.808324] ? netlink_ack+0x4d0/0x4d0 [ 352.809086] ? netlink_deliver_tap+0x62/0x3d0 [ 352.809951] netlink_unicast+0x353/0x480 [ 352.810744] ? netlink_attachskb+0x430/0x430 [ 352.811586] ? __alloc_skb+0xd7/0x200 [ 352.812349] netlink_sendmsg+0x396/0x680 [ 352.813132] ? netlink_unicast+0x480/0x480 [ 352.813952] ? __import_iovec+0x192/0x210 [ 352.814759] ? netlink_unicast+0x480/0x480 [ 352.815580] sock_sendmsg+0x6c/0x80 [ 352.816299] ____sys_sendmsg+0x3a5/0x3c0 [ 352.817096] ? kernel_sendmsg+0x30/0x30 [ 352.817873] ? __ia32_sys_recvmmsg+0x150/0x150 [ 352.818753] ___sys_sendmsg+0xd8/0x140 [ 352.819518] ? sendmsg_copy_msghdr+0x110/0x110 [ 352.820402] ? ___sys_recvmsg+0xf4/0x1a0 [ 352.821110] ? __copy_msghdr_from_user+0x260/0x260 [ 352.821934] ? _raw_spin_lock+0x81/0xd0 [ 352.822680] ? __handle_mm_fault+0xef3/0x1b20 [ 352.823549] ? rb_insert_color+0x2a/0x270 [ 352.824373] ? copy_page_range+0x16b0/0x16b0 [ 352.825209] ? perf_event_update_userpage+0x2d0/0x2d0 [ 352.826190] ? __fget_light+0xd9/0xf0 [ 352.826941] __sys_sendmsg+0xb3/0x130 [ 352.827613] ? __sys_sendmsg_sock+0x20/0x20 [ 352.828377] ? do_user_addr_fault+0x2c5/0x8a0 [ 352.829184] ? fpregs_assert_state_consistent+0x52/0x60 [ 352.830001] ? exit_to_user_mode_prepare+0x32/0x160 [ 352.830845] do_syscall_64+0x35/0x80 [ 352.831445] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 352.832331] RIP: 0033:0x7f7bee973c17 [ ---truncated---