In the Linux kernel, the following vulnerability has been resolved: nfsd: fix potential UAF in nfsd4_cb_getattr_release Once we drop the delegation reference, the fields embedded in it are no longer safe to access. Do that last.

In the Linux kernel, the following vulnerability has been resolved: drm/xe: prevent UAF around preempt fence The fence lock is part of the queue, therefore in the current design anything locking the fence should then also hold a ref to the queue to prevent the queue from being freed. However, currently it looks like we signal the fence and then drop the queue ref, but if something is waiting on the fence, the waiter is kicked to wake up at some later point, where upon waking up it first grabs the lock before checking the fence state. But if we have already dropped the queue ref, then the lock might already be freed as part of the queue, leading to uaf. To prevent this, move the fence lock into the fence itself so we don't run into lifetime issues. Alternative might be to have device level lock, or only release the queue in the fence release callback, however that might require pushing to another worker to avoid locking issues. References: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2454 References: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2342 References: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2020 (cherry picked from commit 7116c35aacedc38be6d15bd21b2fc936eed0008b)

In the Linux kernel, the following vulnerability has been resolved: VMCI: Fix use-after-free when removing resource in vmci_resource_remove() When removing a resource from vmci_resource_table in vmci_resource_remove(), the search is performed using the resource handle by comparing context and resource fields. It is possible though to create two resources with different types but same handle (same context and resource fields). When trying to remove one of the resources, vmci_resource_remove() may not remove the intended one, but the object will still be freed as in the case of the datagram type in vmci_datagram_destroy_handle(). vmci_resource_table will still hold a pointer to this freed resource leading to a use-after-free vulnerability. BUG: KASAN: use-after-free in vmci_handle_is_equal include/linux/vmw_vmci_defs.h:142 [inline] BUG: KASAN: use-after-free in vmci_resource_remove+0x3a1/0x410 drivers/misc/vmw_vmci/vmci_resource.c:147 Read of size 4 at addr ffff88801c16d800 by task syz-executor197/1592 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x82/0xa9 lib/dump_stack.c:106 print_address_description.constprop.0+0x21/0x366 mm/kasan/report.c:239 __kasan_report.cold+0x7f/0x132 mm/kasan/report.c:425 kasan_report+0x38/0x51 mm/kasan/report.c:442 vmci_handle_is_equal include/linux/vmw_vmci_defs.h:142 [inline] vmci_resource_remove+0x3a1/0x410 drivers/misc/vmw_vmci/vmci_resource.c:147 vmci_qp_broker_detach+0x89a/0x11b9 drivers/misc/vmw_vmci/vmci_queue_pair.c:2182 ctx_free_ctx+0x473/0xbe1 drivers/misc/vmw_vmci/vmci_context.c:444 kref_put include/linux/kref.h:65 [inline] vmci_ctx_put drivers/misc/vmw_vmci/vmci_context.c:497 [inline] vmci_ctx_destroy+0x170/0x1d6 drivers/misc/vmw_vmci/vmci_context.c:195 vmci_host_close+0x125/0x1ac drivers/misc/vmw_vmci/vmci_host.c:143 __fput+0x261/0xa34 fs/file_table.c:282 task_work_run+0xf0/0x194 kernel/task_work.c:164 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x184/0x189 kernel/entry/common.c:187 exit_to_user_mode_prepare+0x11b/0x123 kernel/entry/common.c:220 __syscall_exit_to_user_mode_work kernel/entry/common.c:302 [inline] syscall_exit_to_user_mode+0x18/0x42 kernel/entry/common.c:313 do_syscall_64+0x41/0x85 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x6e/0x0 This change ensures the type is also checked when removing the resource from vmci_resource_table in vmci_resource_remove().

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix a use-after-free when hitting errors inside btrfs_submit_chunk() [BUG] There is an internal report that KASAN is reporting use-after-free, with the following backtrace: BUG: KASAN: slab-use-after-free in btrfs_check_read_bio+0xa68/0xb70 [btrfs] Read of size 4 at addr ffff8881117cec28 by task kworker/u16:2/45 CPU: 1 UID: 0 PID: 45 Comm: kworker/u16:2 Not tainted 6.11.0-rc2-next-20240805-default+ #76 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-3-gd478f380-rebuilt.opensuse.org 04/01/2014 Workqueue: btrfs-endio btrfs_end_bio_work [btrfs] Call Trace: dump_stack_lvl+0x61/0x80 print_address_description.constprop.0+0x5e/0x2f0 print_report+0x118/0x216 kasan_report+0x11d/0x1f0 btrfs_check_read_bio+0xa68/0xb70 [btrfs] process_one_work+0xce0/0x12a0 worker_thread+0x717/0x1250 kthread+0x2e3/0x3c0 ret_from_fork+0x2d/0x70 ret_from_fork_asm+0x11/0x20 Allocated by task 20917: kasan_save_stack+0x37/0x60 kasan_save_track+0x10/0x30 __kasan_slab_alloc+0x7d/0x80 kmem_cache_alloc_noprof+0x16e/0x3e0 mempool_alloc_noprof+0x12e/0x310 bio_alloc_bioset+0x3f0/0x7a0 btrfs_bio_alloc+0x2e/0x50 [btrfs] submit_extent_page+0x4d1/0xdb0 [btrfs] btrfs_do_readpage+0x8b4/0x12a0 [btrfs] btrfs_readahead+0x29a/0x430 [btrfs] read_pages+0x1a7/0xc60 page_cache_ra_unbounded+0x2ad/0x560 filemap_get_pages+0x629/0xa20 filemap_read+0x335/0xbf0 vfs_read+0x790/0xcb0 ksys_read+0xfd/0x1d0 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Freed by task 20917: kasan_save_stack+0x37/0x60 kasan_save_track+0x10/0x30 kasan_save_free_info+0x37/0x50 __kasan_slab_free+0x4b/0x60 kmem_cache_free+0x214/0x5d0 bio_free+0xed/0x180 end_bbio_data_read+0x1cc/0x580 [btrfs] btrfs_submit_chunk+0x98d/0x1880 [btrfs] btrfs_submit_bio+0x33/0x70 [btrfs] submit_one_bio+0xd4/0x130 [btrfs] submit_extent_page+0x3ea/0xdb0 [btrfs] btrfs_do_readpage+0x8b4/0x12a0 [btrfs] btrfs_readahead+0x29a/0x430 [btrfs] read_pages+0x1a7/0xc60 page_cache_ra_unbounded+0x2ad/0x560 filemap_get_pages+0x629/0xa20 filemap_read+0x335/0xbf0 vfs_read+0x790/0xcb0 ksys_read+0xfd/0x1d0 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 [CAUSE] Although I cannot reproduce the error, the report itself is good enough to pin down the cause. The call trace is the regular endio workqueue context, but the free-by-task trace is showing that during btrfs_submit_chunk() we already hit a critical error, and is calling btrfs_bio_end_io() to error out. And the original endio function called bio_put() to free the whole bio. This means a double freeing thus causing use-after-free, e.g.: 1. Enter btrfs_submit_bio() with a read bio The read bio length is 128K, crossing two 64K stripes. 2. The first run of btrfs_submit_chunk() 2.1 Call btrfs_map_block(), which returns 64K 2.2 Call btrfs_split_bio() Now there are two bios, one referring to the first 64K, the other referring to the second 64K. 2.3 The first half is submitted. 3. The second run of btrfs_submit_chunk() 3.1 Call btrfs_map_block(), which by somehow failed Now we call btrfs_bio_end_io() to handle the error 3.2 btrfs_bio_end_io() calls the original endio function Which is end_bbio_data_read(), and it calls bio_put() for the original bio. Now the original bio is freed. 4. The submitted first 64K bio finished Now we call into btrfs_check_read_bio() and tries to advance the bio iter. But since the original bio (thus its iter) is already freed, we trigger the above use-after free. And even if the memory is not poisoned/corrupted, we will later call the original endio function, causing a double freeing. [FIX] Instead of calling btrfs_bio_end_io(), call btrfs_orig_bbio_end_io(), which has the extra check on split bios and do the pr ---truncated---

In the Linux kernel, the following vulnerability has been resolved: idpf: fix memory leaks and crashes while performing a soft reset The second tagged commit introduced a UAF, as it removed restoring q_vector->vport pointers after reinitializating the structures. This is due to that all queue allocation functions are performed here with the new temporary vport structure and those functions rewrite the backpointers to the vport. Then, this new struct is freed and the pointers start leading to nowhere. But generally speaking, the current logic is very fragile. It claims to be more reliable when the system is low on memory, but in fact, it consumes two times more memory as at the moment of running this function, there are two vports allocated with their queues and vectors. Moreover, it claims to prevent the driver from running into "bad state", but in fact, any error during the rebuild leaves the old vport in the partially allocated state. Finally, if the interface is down when the function is called, it always allocates a new queue set, but when the user decides to enable the interface later on, vport_open() allocates them once again, IOW there's a clear memory leak here. Just don't allocate a new queue set when performing a reset, that solves crashes and memory leaks. Readd the old queue number and reopen the interface on rollback - that solves limbo states when the device is left disabled and/or without HW queues enabled.

In the Linux kernel, the following vulnerability has been resolved: net: ethernet: mtk_wed: fix use-after-free panic in mtk_wed_setup_tc_block_cb() When there are multiple ap interfaces on one band and with WED on, turning the interface down will cause a kernel panic on MT798X. Previously, cb_priv was freed in mtk_wed_setup_tc_block() without marking NULL,and mtk_wed_setup_tc_block_cb() didn't check the value, too. Assign NULL after free cb_priv in mtk_wed_setup_tc_block() and check NULL in mtk_wed_setup_tc_block_cb(). ---------- Unable to handle kernel paging request at virtual address 0072460bca32b4f5 Call trace: mtk_wed_setup_tc_block_cb+0x4/0x38 0xffffffc0794084bc tcf_block_playback_offloads+0x70/0x1e8 tcf_block_unbind+0x6c/0xc8 ... ---------

The Linux kernel before 5.11.14 has a use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c because the CIPSO and CALIPSO refcounting for the DOI definitions is mishandled, aka CID-ad5d07f4a9cd. This leads to writing an arbitrary value.

In the Linux kernel, the following vulnerability has been resolved: net: bridge: mcast: wait for previous gc cycles when removing port syzbot hit a use-after-free[1] which is caused because the bridge doesn't make sure that all previous garbage has been collected when removing a port. What happens is: CPU 1 CPU 2 start gc cycle remove port acquire gc lock first wait for lock call br_multicasg_gc() directly acquire lock now but free port the port can be freed while grp timers still running Make sure all previous gc cycles have finished by using flush_work before freeing the port. [1] BUG: KASAN: slab-use-after-free in br_multicast_port_group_expired+0x4c0/0x550 net/bridge/br_multicast.c:861 Read of size 8 at addr ffff888071d6d000 by task syz.5.1232/9699 CPU: 1 PID: 9699 Comm: syz.5.1232 Not tainted 6.10.0-rc5-syzkaller-00021-g24ca36a562d6 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 br_multicast_port_group_expired+0x4c0/0x550 net/bridge/br_multicast.c:861 call_timer_fn+0x1a3/0x610 kernel/time/timer.c:1792 expire_timers kernel/time/timer.c:1843 [inline] __run_timers+0x74b/0xaf0 kernel/time/timer.c:2417 __run_timer_base kernel/time/timer.c:2428 [inline] __run_timer_base kernel/time/timer.c:2421 [inline] run_timer_base+0x111/0x190 kernel/time/timer.c:2437

In the Linux kernel, the following vulnerability has been resolved: drm/xe: Free job before xe_exec_queue_put Free job depends on job->vm being valid, the last xe_exec_queue_put can destroy the VM. Prevent UAF by freeing job before xe_exec_queue_put. (cherry picked from commit 32a42c93b74c8ca6d0915ea3eba21bceff53042f)

In the Linux kernel, the following vulnerability has been resolved: ipv6: prevent possible UAF in ip6_xmit() If skb_expand_head() returns NULL, skb has been freed and the associated dst/idev could also have been freed. We must use rcu_read_lock() to prevent a possible UAF.

In the Linux kernel, the following vulnerability has been resolved: idpf: fix UAFs when destroying the queues The second tagged commit started sometimes (very rarely, but possible) throwing WARNs from net/core/page_pool.c:page_pool_disable_direct_recycling(). Turned out idpf frees interrupt vectors with embedded NAPIs *before* freeing the queues making page_pools' NAPI pointers lead to freed memory before these pools are destroyed by libeth. It's not clear whether there are other accesses to the freed vectors when destroying the queues, but anyway, we usually free queue/interrupt vectors only when the queues are destroyed and the NAPIs are guaranteed to not be referenced anywhere. Invert the allocation and freeing logic making queue/interrupt vectors be allocated first and freed last. Vectors don't require queues to be present, so this is safe. Additionally, this change allows to remove that useless queue->q_vector pointer cleanup, as vectors are still valid when freeing the queues (+ both are freed within one function, so it's not clear why nullify the pointers at all).

In the Linux kernel, the following vulnerability has been resolved: atm: idt77252: prevent use after free in dequeue_rx() We can't dereference "skb" after calling vcc->push() because the skb is released.

In Ubuntu's accountsservice an unprivileged local attacker can trigger a use-after-free vulnerability in accountsservice by sending a D-Bus message to the accounts-daemon process.

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to cover read extent cache access with lock syzbot reports a f2fs bug as below: BUG: KASAN: slab-use-after-free in sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46 Read of size 4 at addr ffff8880739ab220 by task syz-executor200/5097 CPU: 0 PID: 5097 Comm: syz-executor200 Not tainted 6.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 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 sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46 do_read_inode fs/f2fs/inode.c:509 [inline] f2fs_iget+0x33e1/0x46e0 fs/f2fs/inode.c:560 f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237 generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413 exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444 exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584 do_handle_to_path fs/fhandle.c:155 [inline] handle_to_path fs/fhandle.c:210 [inline] do_handle_open+0x495/0x650 fs/fhandle.c:226 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f We missed to cover sanity_check_extent_cache() w/ extent cache lock, so, below race case may happen, result in use after free issue. - f2fs_iget - do_read_inode - f2fs_init_read_extent_tree : add largest extent entry in to cache - shrink - f2fs_shrink_read_extent_tree - __shrink_extent_tree - __detach_extent_node : drop largest extent entry - sanity_check_extent_cache : access et->largest w/o lock let's refactor sanity_check_extent_cache() to avoid extent cache access and call it before f2fs_init_read_extent_tree() to fix this issue.

In the Linux kernel, the following vulnerability has been resolved: media: xc2028: avoid use-after-free in load_firmware_cb() syzkaller reported use-after-free in load_firmware_cb() [1]. The reason is because the module allocated a struct tuner in tuner_probe(), and then the module initialization failed, the struct tuner was released. A worker which created during module initialization accesses this struct tuner later, it caused use-after-free. The process is as follows: task-6504 worker_thread tuner_probe <= alloc dvb_frontend [2] ... request_firmware_nowait <= create a worker ... tuner_remove <= free dvb_frontend ... request_firmware_work_func <= the firmware is ready load_firmware_cb <= but now the dvb_frontend has been freed To fix the issue, check the dvd_frontend in load_firmware_cb(), if it is null, report a warning and just return. [1]: ================================================================== BUG: KASAN: use-after-free in load_firmware_cb+0x1310/0x17a0 Read of size 8 at addr ffff8000d7ca2308 by task kworker/2:3/6504 Call trace: load_firmware_cb+0x1310/0x17a0 request_firmware_work_func+0x128/0x220 process_one_work+0x770/0x1824 worker_thread+0x488/0xea0 kthread+0x300/0x430 ret_from_fork+0x10/0x20 Allocated by task 6504: kzalloc tuner_probe+0xb0/0x1430 i2c_device_probe+0x92c/0xaf0 really_probe+0x678/0xcd0 driver_probe_device+0x280/0x370 __device_attach_driver+0x220/0x330 bus_for_each_drv+0x134/0x1c0 __device_attach+0x1f4/0x410 device_initial_probe+0x20/0x30 bus_probe_device+0x184/0x200 device_add+0x924/0x12c0 device_register+0x24/0x30 i2c_new_device+0x4e0/0xc44 v4l2_i2c_new_subdev_board+0xbc/0x290 v4l2_i2c_new_subdev+0xc8/0x104 em28xx_v4l2_init+0x1dd0/0x3770 Freed by task 6504: kfree+0x238/0x4e4 tuner_remove+0x144/0x1c0 i2c_device_remove+0xc8/0x290 __device_release_driver+0x314/0x5fc device_release_driver+0x30/0x44 bus_remove_device+0x244/0x490 device_del+0x350/0x900 device_unregister+0x28/0xd0 i2c_unregister_device+0x174/0x1d0 v4l2_device_unregister+0x224/0x380 em28xx_v4l2_init+0x1d90/0x3770 The buggy address belongs to the object at ffff8000d7ca2000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 776 bytes inside of 2048-byte region [ffff8000d7ca2000, ffff8000d7ca2800) The buggy address belongs to the page: page:ffff7fe00035f280 count:1 mapcount:0 mapping:ffff8000c001f000 index:0x0 flags: 0x7ff800000000100(slab) raw: 07ff800000000100 ffff7fe00049d880 0000000300000003 ffff8000c001f000 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8000d7ca2200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8000d7ca2280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8000d7ca2300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8000d7ca2380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8000d7ca2400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== [2] Actually, it is allocated for struct tuner, and dvb_frontend is inside.

A vulnerability exists in the memory management subsystem of the Linux kernel. The lock handling for accessing and updating virtual memory areas (VMAs) is incorrect, leading to use-after-free problems. This issue can be successfully exploited to execute arbitrary kernel code, escalate containers, and gain root privileges.

In the Linux kernel, the following vulnerability has been resolved: mm: list_lru: fix UAF for memory cgroup The mem_cgroup_from_slab_obj() is supposed to be called under rcu lock or cgroup_mutex or others which could prevent returned memcg from being freed. Fix it by adding missing rcu read lock. Found by code inspection. [songmuchun@bytedance.com: only grab rcu lock when necessary, per Vlastimil]

In the Linux kernel before 5.12.4, net/bluetooth/hci_event.c has a use-after-free when destroying an hci_chan, aka CID-5c4c8c954409. This leads to writing an arbitrary value.

In the Linux kernel, the following vulnerability has been resolved: gtp: fix use-after-free and null-ptr-deref in gtp_newlink() The gtp_link_ops operations structure for the subsystem must be registered after registering the gtp_net_ops pernet operations structure. Syzkaller hit 'general protection fault in gtp_genl_dump_pdp' bug: [ 1010.702740] gtp: GTP module unloaded [ 1010.715877] general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN NOPTI [ 1010.715888] KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] [ 1010.715895] CPU: 1 PID: 128616 Comm: a.out Not tainted 6.8.0-rc6-std-def-alt1 #1 [ 1010.715899] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.0-alt1 04/01/2014 [ 1010.715908] RIP: 0010:gtp_newlink+0x4d7/0x9c0 [gtp] [ 1010.715915] Code: 80 3c 02 00 0f 85 41 04 00 00 48 8b bb d8 05 00 00 e8 ed f6 ff ff 48 89 c2 48 89 c5 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 4f 04 00 00 4c 89 e2 4c 8b 6d 00 48 b8 00 00 00 [ 1010.715920] RSP: 0018:ffff888020fbf180 EFLAGS: 00010203 [ 1010.715929] RAX: dffffc0000000000 RBX: ffff88800399c000 RCX: 0000000000000000 [ 1010.715933] RDX: 0000000000000001 RSI: ffffffff84805280 RDI: 0000000000000282 [ 1010.715938] RBP: 000000000000000d R08: 0000000000000001 R09: 0000000000000000 [ 1010.715942] R10: 0000000000000001 R11: 0000000000000001 R12: ffff88800399cc80 [ 1010.715947] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000400 [ 1010.715953] FS: 00007fd1509ab5c0(0000) GS:ffff88805b300000(0000) knlGS:0000000000000000 [ 1010.715958] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1010.715962] CR2: 0000000000000000 CR3: 000000001c07a000 CR4: 0000000000750ee0 [ 1010.715968] PKRU: 55555554 [ 1010.715972] Call Trace: [ 1010.715985] ? __die_body.cold+0x1a/0x1f [ 1010.715995] ? die_addr+0x43/0x70 [ 1010.716002] ? exc_general_protection+0x199/0x2f0 [ 1010.716016] ? asm_exc_general_protection+0x1e/0x30 [ 1010.716026] ? gtp_newlink+0x4d7/0x9c0 [gtp] [ 1010.716034] ? gtp_net_exit+0x150/0x150 [gtp] [ 1010.716042] __rtnl_newlink+0x1063/0x1700 [ 1010.716051] ? rtnl_setlink+0x3c0/0x3c0 [ 1010.716063] ? is_bpf_text_address+0xc0/0x1f0 [ 1010.716070] ? kernel_text_address.part.0+0xbb/0xd0 [ 1010.716076] ? __kernel_text_address+0x56/0xa0 [ 1010.716084] ? unwind_get_return_address+0x5a/0xa0 [ 1010.716091] ? create_prof_cpu_mask+0x30/0x30 [ 1010.716098] ? arch_stack_walk+0x9e/0xf0 [ 1010.716106] ? stack_trace_save+0x91/0xd0 [ 1010.716113] ? stack_trace_consume_entry+0x170/0x170 [ 1010.716121] ? __lock_acquire+0x15c5/0x5380 [ 1010.716139] ? mark_held_locks+0x9e/0xe0 [ 1010.716148] ? kmem_cache_alloc_trace+0x35f/0x3c0 [ 1010.716155] ? __rtnl_newlink+0x1700/0x1700 [ 1010.716160] rtnl_newlink+0x69/0xa0 [ 1010.716166] rtnetlink_rcv_msg+0x43b/0xc50 [ 1010.716172] ? rtnl_fdb_dump+0x9f0/0x9f0 [ 1010.716179] ? lock_acquire+0x1fe/0x560 [ 1010.716188] ? netlink_deliver_tap+0x12f/0xd50 [ 1010.716196] netlink_rcv_skb+0x14d/0x440 [ 1010.716202] ? rtnl_fdb_dump+0x9f0/0x9f0 [ 1010.716208] ? netlink_ack+0xab0/0xab0 [ 1010.716213] ? netlink_deliver_tap+0x202/0xd50 [ 1010.716220] ? netlink_deliver_tap+0x218/0xd50 [ 1010.716226] ? __virt_addr_valid+0x30b/0x590 [ 1010.716233] netlink_unicast+0x54b/0x800 [ 1010.716240] ? netlink_attachskb+0x870/0x870 [ 1010.716248] ? __check_object_size+0x2de/0x3b0 [ 1010.716254] netlink_sendmsg+0x938/0xe40 [ 1010.716261] ? netlink_unicast+0x800/0x800 [ 1010.716269] ? __import_iovec+0x292/0x510 [ 1010.716276] ? netlink_unicast+0x800/0x800 [ 1010.716284] __sock_sendmsg+0x159/0x190 [ 1010.716290] ____sys_sendmsg+0x712/0x880 [ 1010.716297] ? sock_write_iter+0x3d0/0x3d0 [ 1010.716304] ? __ia32_sys_recvmmsg+0x270/0x270 [ 1010.716309] ? lock_acquire+0x1fe/0x560 [ 1010.716315] ? drain_array_locked+0x90/0x90 [ 1010.716324] ___sys_sendmsg+0xf8/0x170 [ 1010.716331] ? sendmsg_copy_msghdr+0x170/0x170 [ 1010.716337] ? lockdep_init_map ---truncated---

In the Linux kernel, the following vulnerability has been resolved: media: venus: fix use after free in vdec_close There appears to be a possible use after free with vdec_close(). The firmware will add buffer release work to the work queue through HFI callbacks as a normal part of decoding. Randomly closing the decoder device from userspace during normal decoding can incur a read after free for inst. Fix it by cancelling the work in vdec_close.

In the Linux kernel, the following vulnerability has been resolved: mISDN: Fix a use after free in hfcmulti_tx() Don't dereference *sp after calling dev_kfree_skb(*sp).

In the Linux kernel, the following vulnerability has been resolved: RDMA/iwcm: Fix a use-after-free related to destroying CM IDs iw_conn_req_handler() associates a new struct rdma_id_private (conn_id) with an existing struct iw_cm_id (cm_id) as follows: conn_id->cm_id.iw = cm_id; cm_id->context = conn_id; cm_id->cm_handler = cma_iw_handler; rdma_destroy_id() frees both the cm_id and the struct rdma_id_private. Make sure that cm_work_handler() does not trigger a use-after-free by only freeing of the struct rdma_id_private after all pending work has finished.

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix extent map use-after-free when adding pages to compressed bio At add_ra_bio_pages() we are accessing the extent map to calculate 'add_size' after we dropped our reference on the extent map, resulting in a use-after-free. Fix this by computing 'add_size' before dropping our extent map reference.

In the Linux kernel through 6.3.1, a use-after-free in Netfilter nf_tables when processing batch requests can be abused to perform arbitrary read and write operations on kernel memory. Unprivileged local users can obtain root privileges. This occurs because anonymous sets are mishandled.

An issue was discovered in the Linux kernel through 5.10.11. PI futexes have a kernel stack use-after-free during fault handling, allowing local users to execute code in the kernel, aka CID-34b1a1ce1458.

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_qca: Fix driver shutdown on closed serdev The driver shutdown callback (which sends EDL_SOC_RESET to the device over serdev) should not be invoked when HCI device is not open (e.g. if hci_dev_open_sync() failed), because the serdev and its TTY are not open either. Also skip this step if device is powered off (qca_power_shutdown()). The shutdown callback causes use-after-free during system reboot with Qualcomm Atheros Bluetooth: Unable to handle kernel paging request at virtual address 0072662f67726fd7 ... CPU: 6 PID: 1 Comm: systemd-shutdow Tainted: G W 6.1.0-rt5-00325-g8a5f56bcfcca #8 Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT) Call trace: tty_driver_flush_buffer+0x4/0x30 serdev_device_write_flush+0x24/0x34 qca_serdev_shutdown+0x80/0x130 [hci_uart] device_shutdown+0x15c/0x260 kernel_restart+0x48/0xac KASAN report: BUG: KASAN: use-after-free in tty_driver_flush_buffer+0x1c/0x50 Read of size 8 at addr ffff16270c2e0018 by task systemd-shutdow/1 CPU: 7 PID: 1 Comm: systemd-shutdow Not tainted 6.1.0-next-20221220-00014-gb85aaf97fb01-dirty #28 Hardware name: Qualcomm Technologies, Inc. Robotics RB5 (DT) Call trace: dump_backtrace.part.0+0xdc/0xf0 show_stack+0x18/0x30 dump_stack_lvl+0x68/0x84 print_report+0x188/0x488 kasan_report+0xa4/0xf0 __asan_load8+0x80/0xac tty_driver_flush_buffer+0x1c/0x50 ttyport_write_flush+0x34/0x44 serdev_device_write_flush+0x48/0x60 qca_serdev_shutdown+0x124/0x274 device_shutdown+0x1e8/0x350 kernel_restart+0x48/0xb0 __do_sys_reboot+0x244/0x2d0 __arm64_sys_reboot+0x54/0x70 invoke_syscall+0x60/0x190 el0_svc_common.constprop.0+0x7c/0x160 do_el0_svc+0x44/0xf0 el0_svc+0x2c/0x6c el0t_64_sync_handler+0xbc/0x140 el0t_64_sync+0x190/0x194

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix UAF due to race between btf_try_get_module and load_module While working on code to populate kfunc BTF ID sets for module BTF from its initcall, I noticed that by the time the initcall is invoked, the module BTF can already be seen by userspace (and the BPF verifier). The existing btf_try_get_module calls try_module_get which only fails if mod->state == MODULE_STATE_GOING, i.e. it can increment module reference when module initcall is happening in parallel. Currently, BTF parsing happens from MODULE_STATE_COMING notifier callback. At this point, the module initcalls have not been invoked. The notifier callback parses and prepares the module BTF, allocates an ID, which publishes it to userspace, and then adds it to the btf_modules list allowing the kernel to invoke btf_try_get_module for the BTF. However, at this point, the module has not been fully initialized (i.e. its initcalls have not finished). The code in module.c can still fail and free the module, without caring for other users. However, nothing stops btf_try_get_module from succeeding between the state transition from MODULE_STATE_COMING to MODULE_STATE_LIVE. This leads to a use-after-free issue when BPF program loads successfully in the state transition, load_module's do_init_module call fails and frees the module, and BPF program fd on close calls module_put for the freed module. Future patch has test case to verify we don't regress in this area in future. There are multiple points after prepare_coming_module (in load_module) where failure can occur and module loading can return error. We illustrate and test for the race using the last point where it can practically occur (in module __init function). An illustration of the race: CPU 0 CPU 1 load_module notifier_call(MODULE_STATE_COMING) btf_parse_module btf_alloc_id // Published to userspace list_add(&btf_mod->list, btf_modules) mod->init(...) ... ^ bpf_check | check_pseudo_btf_id | btf_try_get_module | returns true | ... ... | module __init in progress return prog_fd | ... ... V if (ret < 0) free_module(mod) ... close(prog_fd) ... bpf_prog_free_deferred module_put(used_btf.mod) // use-after-free We fix this issue by setting a flag BTF_MODULE_F_LIVE, from the notifier callback when MODULE_STATE_LIVE state is reached for the module, so that we return NULL from btf_try_get_module for modules that are not fully formed. Since try_module_get already checks that module is not in MODULE_STATE_GOING state, and that is the only transition a live module can make before being removed from btf_modules list, this is enough to close the race and prevent the bug. A later selftest patch crafts the race condition artifically to verify that it has been fixed, and that verifier fails to load program (with ENXIO). Lastly, a couple of comments: 1. Even if this race didn't exist, it seems more appropriate to only access resources (ksyms and kfuncs) of a fully formed module which has been initialized completely. 2. This patch was born out of need for synchronization against module initcall for the next patch, so it is needed for correctness even without the aforementioned race condition. The BTF resources initialized by module initcall are set up once and then only looked up, so just waiting until the initcall has finished ensures correct behavior.

In the Linux kernel, the following vulnerability has been resolved: nilfs2: add missing check for inode numbers on directory entries Syzbot reported that mounting and unmounting a specific pattern of corrupted nilfs2 filesystem images causes a use-after-free of metadata file inodes, which triggers a kernel bug in lru_add_fn(). As Jan Kara pointed out, this is because the link count of a metadata file gets corrupted to 0, and nilfs_evict_inode(), which is called from iput(), tries to delete that inode (ifile inode in this case). The inconsistency occurs because directories containing the inode numbers of these metadata files that should not be visible in the namespace are read without checking. Fix this issue by treating the inode numbers of these internal files as errors in the sanity check helper when reading directory folios/pages. Also thanks to Hillf Danton and Matthew Wilcox for their initial mm-layer analysis.

In the Linux kernel, the following vulnerability has been resolved: KVM: PPC: Book3S HV: Prevent UAF in kvm_spapr_tce_attach_iommu_group() Al reported a possible use-after-free (UAF) in kvm_spapr_tce_attach_iommu_group(). It looks up `stt` from tablefd, but then continues to use it after doing fdput() on the returned fd. After the fdput() the tablefd is free to be closed by another thread. The close calls kvm_spapr_tce_release() and then release_spapr_tce_table() (via call_rcu()) which frees `stt`. Although there are calls to rcu_read_lock() in kvm_spapr_tce_attach_iommu_group() they are not sufficient to prevent the UAF, because `stt` is used outside the locked regions. With an artifcial delay after the fdput() and a userspace program which triggers the race, KASAN detects the UAF: BUG: KASAN: slab-use-after-free in kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm] Read of size 4 at addr c000200027552c30 by task kvm-vfio/2505 CPU: 54 PID: 2505 Comm: kvm-vfio Not tainted 6.10.0-rc3-next-20240612-dirty #1 Hardware name: 8335-GTH POWER9 0x4e1202 opal:skiboot-v6.5.3-35-g1851b2a06 PowerNV Call Trace: dump_stack_lvl+0xb4/0x108 (unreliable) print_report+0x2b4/0x6ec kasan_report+0x118/0x2b0 __asan_load4+0xb8/0xd0 kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm] kvm_vfio_set_attr+0x524/0xac0 [kvm] kvm_device_ioctl+0x144/0x240 [kvm] sys_ioctl+0x62c/0x1810 system_call_exception+0x190/0x440 system_call_vectored_common+0x15c/0x2ec ... Freed by task 0: ... kfree+0xec/0x3e0 release_spapr_tce_table+0xd4/0x11c [kvm] rcu_core+0x568/0x16a0 handle_softirqs+0x23c/0x920 do_softirq_own_stack+0x6c/0x90 do_softirq_own_stack+0x58/0x90 __irq_exit_rcu+0x218/0x2d0 irq_exit+0x30/0x80 arch_local_irq_restore+0x128/0x230 arch_local_irq_enable+0x1c/0x30 cpuidle_enter_state+0x134/0x5cc cpuidle_enter+0x6c/0xb0 call_cpuidle+0x7c/0x100 do_idle+0x394/0x410 cpu_startup_entry+0x60/0x70 start_secondary+0x3fc/0x410 start_secondary_prolog+0x10/0x14 Fix it by delaying the fdput() until `stt` is no longer in use, which is effectively the entire function. To keep the patch minimal add a call to fdput() at each of the existing return paths. Future work can convert the function to goto or __cleanup style cleanup. With the fix in place the test case no longer triggers the UAF.

In the Linux kernel, the following vulnerability has been resolved: usb: typec: tcpm: fix use-after-free case in tcpm_register_source_caps There could be a potential use-after-free case in tcpm_register_source_caps(). This could happen when: * new (say invalid) source caps are advertised * the existing source caps are unregistered * tcpm_register_source_caps() returns with an error as usb_power_delivery_register_capabilities() fails This causes port->partner_source_caps to hold on to the now freed source caps. Reset port->partner_source_caps value to NULL after unregistering existing source caps.

In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: Fix possible Use-After-Free in irq_process_work_list Use list_for_each_entry_safe() to allow iterating through the list and deleting the entry in the iteration process. The descriptor is freed via idxd_desc_complete() and there's a slight chance may cause issue for the list iterator when the descriptor is reused by another thread without it being deleted from the list.

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Always stop health timer during driver removal Currently, if teardown_hca fails to execute during driver removal, mlx5 does not stop the health timer. Afterwards, mlx5 continue with driver teardown. This may lead to a UAF bug, which results in page fault Oops[1], since the health timer invokes after resources were freed. Hence, stop the health monitor even if teardown_hca fails. [1] mlx5_core 0000:18:00.0: E-Switch: Unload vfs: mode(LEGACY), nvfs(0), necvfs(0), active vports(0) mlx5_core 0000:18:00.0: E-Switch: Disable: mode(LEGACY), nvfs(0), necvfs(0), active vports(0) mlx5_core 0000:18:00.0: E-Switch: Disable: mode(LEGACY), nvfs(0), necvfs(0), active vports(0) mlx5_core 0000:18:00.0: E-Switch: cleanup mlx5_core 0000:18:00.0: wait_func:1155:(pid 1967079): TEARDOWN_HCA(0x103) timeout. Will cause a leak of a command resource mlx5_core 0000:18:00.0: mlx5_function_close:1288:(pid 1967079): tear_down_hca failed, skip cleanup BUG: unable to handle page fault for address: ffffa26487064230 PGD 100c00067 P4D 100c00067 PUD 100e5a067 PMD 105ed7067 PTE 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 0 Comm: swapper/0 Tainted: G OE ------- --- 6.7.0-68.fc38.x86_64 #1 Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0013.121520200651 12/15/2020 RIP: 0010:ioread32be+0x34/0x60 RSP: 0018:ffffa26480003e58 EFLAGS: 00010292 RAX: ffffa26487064200 RBX: ffff9042d08161a0 RCX: ffff904c108222c0 RDX: 000000010bbf1b80 RSI: ffffffffc055ddb0 RDI: ffffa26487064230 RBP: ffff9042d08161a0 R08: 0000000000000022 R09: ffff904c108222e8 R10: 0000000000000004 R11: 0000000000000441 R12: ffffffffc055ddb0 R13: ffffa26487064200 R14: ffffa26480003f00 R15: ffff904c108222c0 FS: 0000000000000000(0000) GS:ffff904c10800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffa26487064230 CR3: 00000002c4420006 CR4: 00000000007706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <IRQ> ? __die+0x23/0x70 ? page_fault_oops+0x171/0x4e0 ? exc_page_fault+0x175/0x180 ? asm_exc_page_fault+0x26/0x30 ? __pfx_poll_health+0x10/0x10 [mlx5_core] ? __pfx_poll_health+0x10/0x10 [mlx5_core] ? ioread32be+0x34/0x60 mlx5_health_check_fatal_sensors+0x20/0x100 [mlx5_core] ? __pfx_poll_health+0x10/0x10 [mlx5_core] poll_health+0x42/0x230 [mlx5_core] ? __next_timer_interrupt+0xbc/0x110 ? __pfx_poll_health+0x10/0x10 [mlx5_core] call_timer_fn+0x21/0x130 ? __pfx_poll_health+0x10/0x10 [mlx5_core] __run_timers+0x222/0x2c0 run_timer_softirq+0x1d/0x40 __do_softirq+0xc9/0x2c8 __irq_exit_rcu+0xa6/0xc0 sysvec_apic_timer_interrupt+0x72/0x90 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 RIP: 0010:cpuidle_enter_state+0xcc/0x440 ? cpuidle_enter_state+0xbd/0x440 cpuidle_enter+0x2d/0x40 do_idle+0x20d/0x270 cpu_startup_entry+0x2a/0x30 rest_init+0xd0/0xd0 arch_call_rest_init+0xe/0x30 start_kernel+0x709/0xa90 x86_64_start_reservations+0x18/0x30 x86_64_start_kernel+0x96/0xa0 secondary_startup_64_no_verify+0x18f/0x19b ---[ end trace 0000000000000000 ]---

In the Linux kernel, the following vulnerability has been resolved: net: do not leave a dangling sk pointer, when socket creation fails It is possible to trigger a use-after-free by: * attaching an fentry probe to __sock_release() and the probe calling the bpf_get_socket_cookie() helper * running traceroute -I 1.1.1.1 on a freshly booted VM A KASAN enabled kernel will log something like below (decoded and stripped): ================================================================== BUG: KASAN: slab-use-after-free in __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29) Read of size 8 at addr ffff888007110dd8 by task traceroute/299 CPU: 2 PID: 299 Comm: traceroute Tainted: G E 6.10.0-rc2+ #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:117 (discriminator 1)) print_report (mm/kasan/report.c:378 mm/kasan/report.c:488) ? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29) kasan_report (mm/kasan/report.c:603) ? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29) kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189) __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29) bpf_get_socket_ptr_cookie (./arch/x86/include/asm/preempt.h:94 ./include/linux/sock_diag.h:42 net/core/filter.c:5094 net/core/filter.c:5092) bpf_prog_875642cf11f1d139___sock_release+0x6e/0x8e bpf_trampoline_6442506592+0x47/0xaf __sock_release (net/socket.c:652) __sock_create (net/socket.c:1601) ... Allocated by task 299 on cpu 2 at 78.328492s: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:68) __kasan_slab_alloc (mm/kasan/common.c:312 mm/kasan/common.c:338) kmem_cache_alloc_noprof (mm/slub.c:3941 mm/slub.c:4000 mm/slub.c:4007) sk_prot_alloc (net/core/sock.c:2075) sk_alloc (net/core/sock.c:2134) inet_create (net/ipv4/af_inet.c:327 net/ipv4/af_inet.c:252) __sock_create (net/socket.c:1572) __sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706) __x64_sys_socket (net/socket.c:1718) do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Freed by task 299 on cpu 2 at 78.328502s: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:68) kasan_save_free_info (mm/kasan/generic.c:582) poison_slab_object (mm/kasan/common.c:242) __kasan_slab_free (mm/kasan/common.c:256) kmem_cache_free (mm/slub.c:4437 mm/slub.c:4511) __sk_destruct (net/core/sock.c:2117 net/core/sock.c:2208) inet_create (net/ipv4/af_inet.c:397 net/ipv4/af_inet.c:252) __sock_create (net/socket.c:1572) __sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706) __x64_sys_socket (net/socket.c:1718) do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Fix this by clearing the struct socket reference in sk_common_release() to cover all protocol families create functions, which may already attached the reference to the sk object with sock_init_data().

In the Linux kernel, the following vulnerability has been resolved: netns: Make get_net_ns() handle zero refcount net Syzkaller hit a warning: refcount_t: addition on 0; use-after-free. WARNING: CPU: 3 PID: 7890 at lib/refcount.c:25 refcount_warn_saturate+0xdf/0x1d0 Modules linked in: CPU: 3 PID: 7890 Comm: tun Not tainted 6.10.0-rc3-00100-gcaa4f9578aba-dirty #310 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:refcount_warn_saturate+0xdf/0x1d0 Code: 41 49 04 31 ff 89 de e8 9f 1e cd fe 84 db 75 9c e8 76 26 cd fe c6 05 b6 41 49 04 01 90 48 c7 c7 b8 8e 25 86 e8 d2 05 b5 fe 90 <0f> 0b 90 90 e9 79 ff ff ff e8 53 26 cd fe 0f b6 1 RSP: 0018:ffff8881067b7da0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff811c72ac RDX: ffff8881026a2140 RSI: ffffffff811c72b5 RDI: 0000000000000001 RBP: ffff8881067b7db0 R08: 0000000000000000 R09: 205b5d3730353139 R10: 0000000000000000 R11: 205d303938375420 R12: ffff8881086500c4 R13: ffff8881086500c4 R14: ffff8881086500b0 R15: ffff888108650040 FS: 00007f5b2961a4c0(0000) GS:ffff88823bd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d7ed36fd18 CR3: 00000001482f6000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? show_regs+0xa3/0xc0 ? __warn+0xa5/0x1c0 ? refcount_warn_saturate+0xdf/0x1d0 ? report_bug+0x1fc/0x2d0 ? refcount_warn_saturate+0xdf/0x1d0 ? handle_bug+0xa1/0x110 ? exc_invalid_op+0x3c/0xb0 ? asm_exc_invalid_op+0x1f/0x30 ? __warn_printk+0xcc/0x140 ? __warn_printk+0xd5/0x140 ? refcount_warn_saturate+0xdf/0x1d0 get_net_ns+0xa4/0xc0 ? __pfx_get_net_ns+0x10/0x10 open_related_ns+0x5a/0x130 __tun_chr_ioctl+0x1616/0x2370 ? __sanitizer_cov_trace_switch+0x58/0xa0 ? __sanitizer_cov_trace_const_cmp2+0x1c/0x30 ? __pfx_tun_chr_ioctl+0x10/0x10 tun_chr_ioctl+0x2f/0x40 __x64_sys_ioctl+0x11b/0x160 x64_sys_call+0x1211/0x20d0 do_syscall_64+0x9e/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5b28f165d7 Code: b3 66 90 48 8b 05 b1 48 2d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 81 48 2d 00 8 RSP: 002b:00007ffc2b59c5e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5b28f165d7 RDX: 0000000000000000 RSI: 00000000000054e3 RDI: 0000000000000003 RBP: 00007ffc2b59c650 R08: 00007f5b291ed8c0 R09: 00007f5b2961a4c0 R10: 0000000029690010 R11: 0000000000000246 R12: 0000000000400730 R13: 00007ffc2b59cf40 R14: 0000000000000000 R15: 0000000000000000 </TASK> Kernel panic - not syncing: kernel: panic_on_warn set ... This is trigger as below: ns0 ns1 tun_set_iff() //dev is tun0 tun->dev = dev //ip link set tun0 netns ns1 put_net() //ref is 0 __tun_chr_ioctl() //TUNGETDEVNETNS net = dev_net(tun->dev); open_related_ns(&net->ns, get_net_ns); //ns1 get_net_ns() get_net() //addition on 0 Use maybe_get_net() in get_net_ns in case net's ref is zero to fix this

A use after free vulnerability was found in prepare_to_relocate in fs/btrfs/relocation.c in btrfs in the Linux Kernel. This possible flaw can be triggered by calling btrfs_ioctl_balance() before calling btrfs_ioctl_defrag().

In the Linux kernel, the following vulnerability has been resolved: e100: Fix possible use after free in e100_xmit_prepare In e100_xmit_prepare(), if we can't map the skb, then return -ENOMEM, so e100_xmit_frame() will return NETDEV_TX_BUSY and the upper layer will resend the skb. But the skb is already freed, which will cause UAF bug when the upper layer resends the skb. Remove the harmful free.

In the Linux kernel, the following vulnerability has been resolved: block: avoid to reuse `hctx` not removed from cpuhp callback list If the 'hctx' isn't removed from cpuhp callback list, we can't reuse it, otherwise use-after-free may be triggered.

In the Linux kernel, the following vulnerability has been resolved: powerpc/pseries: Fix use after free in remove_phb_dynamic() In remove_phb_dynamic() we use &phb->io_resource, after we've called device_unregister(&host_bridge->dev). But the unregister may have freed phb, because pcibios_free_controller_deferred() is the release function for the host_bridge. If there are no outstanding references when we call device_unregister() then phb will be freed out from under us. This has gone mainly unnoticed, but with slub_debug and page_poison enabled it can lead to a crash: PID: 7574 TASK: c0000000d492cb80 CPU: 13 COMMAND: "drmgr" #0 [c0000000e4f075a0] crash_kexec at c00000000027d7dc #1 [c0000000e4f075d0] oops_end at c000000000029608 #2 [c0000000e4f07650] __bad_page_fault at c0000000000904b4 #3 [c0000000e4f076c0] do_bad_slb_fault at c00000000009a5a8 #4 [c0000000e4f076f0] data_access_slb_common_virt at c000000000008b30 Data SLB Access [380] exception frame: R0: c000000000167250 R1: c0000000e4f07a00 R2: c000000002a46100 R3: c000000002b39ce8 R4: 00000000000000c0 R5: 00000000000000a9 R6: 3894674d000000c0 R7: 0000000000000000 R8: 00000000000000ff R9: 0000000000000100 R10: 6b6b6b6b6b6b6b6b R11: 0000000000008000 R12: c00000000023da80 R13: c0000009ffd38b00 R14: 0000000000000000 R15: 000000011c87f0f0 R16: 0000000000000006 R17: 0000000000000003 R18: 0000000000000002 R19: 0000000000000004 R20: 0000000000000005 R21: 000000011c87ede8 R22: 000000011c87c5a8 R23: 000000011c87d3a0 R24: 0000000000000000 R25: 0000000000000001 R26: c0000000e4f07cc8 R27: c00000004d1cc400 R28: c0080000031d00e8 R29: c00000004d23d800 R30: c00000004d1d2400 R31: c00000004d1d2540 NIP: c000000000167258 MSR: 8000000000009033 OR3: c000000000e9f474 CTR: 0000000000000000 LR: c000000000167250 XER: 0000000020040003 CCR: 0000000024088420 MQ: 0000000000000000 DAR: 6b6b6b6b6b6b6ba3 DSISR: c0000000e4f07920 Syscall Result: fffffffffffffff2 [NIP : release_resource+56] [LR : release_resource+48] #5 [c0000000e4f07a00] release_resource at c000000000167258 (unreliable) #6 [c0000000e4f07a30] remove_phb_dynamic at c000000000105648 #7 [c0000000e4f07ab0] dlpar_remove_slot at c0080000031a09e8 [rpadlpar_io] #8 [c0000000e4f07b50] remove_slot_store at c0080000031a0b9c [rpadlpar_io] #9 [c0000000e4f07be0] kobj_attr_store at c000000000817d8c #10 [c0000000e4f07c00] sysfs_kf_write at c00000000063e504 #11 [c0000000e4f07c20] kernfs_fop_write_iter at c00000000063d868 #12 [c0000000e4f07c70] new_sync_write at c00000000054339c #13 [c0000000e4f07d10] vfs_write at c000000000546624 #14 [c0000000e4f07d60] ksys_write at c0000000005469f4 #15 [c0000000e4f07db0] system_call_exception at c000000000030840 #16 [c0000000e4f07e10] system_call_vectored_common at c00000000000c168 To avoid it, we can take a reference to the host_bridge->dev until we're done using phb. Then when we drop the reference the phb will be freed.

In the Linux kernel, the following vulnerability has been resolved: cachefiles: fix slab-use-after-free in cachefiles_ondemand_get_fd() We got the following issue in a fuzz test of randomly issuing the restore command: ================================================================== BUG: KASAN: slab-use-after-free in cachefiles_ondemand_daemon_read+0x609/0xab0 Write of size 4 at addr ffff888109164a80 by task ondemand-04-dae/4962 CPU: 11 PID: 4962 Comm: ondemand-04-dae Not tainted 6.8.0-rc7-dirty #542 Call Trace: kasan_report+0x94/0xc0 cachefiles_ondemand_daemon_read+0x609/0xab0 vfs_read+0x169/0xb50 ksys_read+0xf5/0x1e0 Allocated by task 626: __kmalloc+0x1df/0x4b0 cachefiles_ondemand_send_req+0x24d/0x690 cachefiles_create_tmpfile+0x249/0xb30 cachefiles_create_file+0x6f/0x140 cachefiles_look_up_object+0x29c/0xa60 cachefiles_lookup_cookie+0x37d/0xca0 fscache_cookie_state_machine+0x43c/0x1230 [...] Freed by task 626: kfree+0xf1/0x2c0 cachefiles_ondemand_send_req+0x568/0x690 cachefiles_create_tmpfile+0x249/0xb30 cachefiles_create_file+0x6f/0x140 cachefiles_look_up_object+0x29c/0xa60 cachefiles_lookup_cookie+0x37d/0xca0 fscache_cookie_state_machine+0x43c/0x1230 [...] ================================================================== Following is the process that triggers the issue: mount | daemon_thread1 | daemon_thread2 ------------------------------------------------------------ cachefiles_ondemand_init_object cachefiles_ondemand_send_req REQ_A = kzalloc(sizeof(*req) + data_len) wait_for_completion(&REQ_A->done) cachefiles_daemon_read cachefiles_ondemand_daemon_read REQ_A = cachefiles_ondemand_select_req cachefiles_ondemand_get_fd copy_to_user(_buffer, msg, n) process_open_req(REQ_A) ------ restore ------ cachefiles_ondemand_restore xas_for_each(&xas, req, ULONG_MAX) xas_set_mark(&xas, CACHEFILES_REQ_NEW); cachefiles_daemon_read cachefiles_ondemand_daemon_read REQ_A = cachefiles_ondemand_select_req write(devfd, ("copen %u,%llu", msg->msg_id, size)); cachefiles_ondemand_copen xa_erase(&cache->reqs, id) complete(&REQ_A->done) kfree(REQ_A) cachefiles_ondemand_get_fd(REQ_A) fd = get_unused_fd_flags file = anon_inode_getfile fd_install(fd, file) load = (void *)REQ_A->msg.data; load->fd = fd; // load UAF !!! This issue is caused by issuing a restore command when the daemon is still alive, which results in a request being processed multiple times thus triggering a UAF. So to avoid this problem, add an additional reference count to cachefiles_req, which is held while waiting and reading, and then released when the waiting and reading is over. Note that since there is only one reference count for waiting, we need to avoid the same request being completed multiple times, so we can only complete the request if it is successfully removed from the xarray.

In the Linux kernel, the following vulnerability has been resolved: ima: Fix use-after-free on a dentry's dname.name ->d_name.name can change on rename and the earlier value can be freed; there are conditions sufficient to stabilize it (->d_lock on dentry, ->d_lock on its parent, ->i_rwsem exclusive on the parent's inode, rename_lock), but none of those are met at any of the sites. Take a stable snapshot of the name instead.

A use-after-free vulnerability was found in the Linux kernel's netfilter subsystem in net/netfilter/nf_tables_api.c. Mishandled error handling with NFT_MSG_NEWRULE makes it possible to use a dangling pointer in the same transaction causing a use-after-free vulnerability. This flaw allows a local attacker with user access to cause a privilege escalation issue. We recommend upgrading past commit 1240eb93f0616b21c675416516ff3d74798fdc97.

In the Linux kernel, the following vulnerability has been resolved: net/mlx5: Discard command completions in internal error Fix use after free when FW completion arrives while device is in internal error state. Avoid calling completion handler in this case, since the device will flush the command interface and trigger all completions manually. Kernel log: ------------[ cut here ]------------ refcount_t: underflow; use-after-free. ... RIP: 0010:refcount_warn_saturate+0xd8/0xe0 ... Call Trace: <IRQ> ? __warn+0x79/0x120 ? refcount_warn_saturate+0xd8/0xe0 ? report_bug+0x17c/0x190 ? handle_bug+0x3c/0x60 ? exc_invalid_op+0x14/0x70 ? asm_exc_invalid_op+0x16/0x20 ? refcount_warn_saturate+0xd8/0xe0 cmd_ent_put+0x13b/0x160 [mlx5_core] mlx5_cmd_comp_handler+0x5f9/0x670 [mlx5_core] cmd_comp_notifier+0x1f/0x30 [mlx5_core] notifier_call_chain+0x35/0xb0 atomic_notifier_call_chain+0x16/0x20 mlx5_eq_async_int+0xf6/0x290 [mlx5_core] notifier_call_chain+0x35/0xb0 atomic_notifier_call_chain+0x16/0x20 irq_int_handler+0x19/0x30 [mlx5_core] __handle_irq_event_percpu+0x4b/0x160 handle_irq_event+0x2e/0x80 handle_edge_irq+0x98/0x230 __common_interrupt+0x3b/0xa0 common_interrupt+0x7b/0xa0 </IRQ> <TASK> asm_common_interrupt+0x22/0x40

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/mes: fix use-after-free issue Delete fence fallback timer to fix the ramdom use-after-free issue. v2: move to amdgpu_mes.c

In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix potential glock use-after-free on unmount When a DLM lockspace is released and there ares still locks in that lockspace, DLM will unlock those locks automatically. Commit fb6791d100d1b started exploiting this behavior to speed up filesystem unmount: gfs2 would simply free glocks it didn't want to unlock and then release the lockspace. This didn't take the bast callbacks for asynchronous lock contention notifications into account, which remain active until until a lock is unlocked or its lockspace is released. To prevent those callbacks from accessing deallocated objects, put the glocks that should not be unlocked on the sd_dead_glocks list, release the lockspace, and only then free those glocks. As an additional measure, ignore unexpected ast and bast callbacks if the receiving glock is dead.

A flaw was found in the Linux kernel’s futex implementation. This flaw allows a local attacker to corrupt system memory or escalate their privileges when creating a futex on a filesystem that is about to be unmounted. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix use-after-free of timer for log writer thread Patch series "nilfs2: fix log writer related issues". This bug fix series covers three nilfs2 log writer-related issues, including a timer use-after-free issue and potential deadlock issue on unmount, and a potential freeze issue in event synchronization found during their analysis. Details are described in each commit log. This patch (of 3): A use-after-free issue has been reported regarding the timer sc_timer on the nilfs_sc_info structure. The problem is that even though it is used to wake up a sleeping log writer thread, sc_timer is not shut down until the nilfs_sc_info structure is about to be freed, and is used regardless of the thread's lifetime. Fix this issue by limiting the use of sc_timer only while the log writer thread is alive.

In the Linux kernel, the following vulnerability has been resolved: watchdog: cpu5wdt.c: Fix use-after-free bug caused by cpu5wdt_trigger When the cpu5wdt module is removing, the origin code uses del_timer() to de-activate the timer. If the timer handler is running, del_timer() could not stop it and will return directly. If the port region is released by release_region() and then the timer handler cpu5wdt_trigger() calls outb() to write into the region that is released, the use-after-free bug will happen. Change del_timer() to timer_shutdown_sync() in order that the timer handler could be finished before the port region is released.

In the Linux kernel, the following vulnerability has been resolved: RDMA/hns: Fix UAF for cq async event The refcount of CQ is not protected by locks. When CQ asynchronous events and CQ destruction are concurrent, CQ may have been released, which will cause UAF. Use the xa_lock() to protect the CQ refcount.

In the Linux kernel, the following vulnerability has been resolved: ftrace: Fix possible use-after-free issue in ftrace_location() KASAN reports a bug: BUG: KASAN: use-after-free in ftrace_location+0x90/0x120 Read of size 8 at addr ffff888141d40010 by task insmod/424 CPU: 8 PID: 424 Comm: insmod Tainted: G W 6.9.0-rc2+ [...] Call Trace: <TASK> dump_stack_lvl+0x68/0xa0 print_report+0xcf/0x610 kasan_report+0xb5/0xe0 ftrace_location+0x90/0x120 register_kprobe+0x14b/0xa40 kprobe_init+0x2d/0xff0 [kprobe_example] do_one_initcall+0x8f/0x2d0 do_init_module+0x13a/0x3c0 load_module+0x3082/0x33d0 init_module_from_file+0xd2/0x130 __x64_sys_finit_module+0x306/0x440 do_syscall_64+0x68/0x140 entry_SYSCALL_64_after_hwframe+0x71/0x79 The root cause is that, in lookup_rec(), ftrace record of some address is being searched in ftrace pages of some module, but those ftrace pages at the same time is being freed in ftrace_release_mod() as the corresponding module is being deleted: CPU1 | CPU2 register_kprobes() { | delete_module() { check_kprobe_address_safe() { | arch_check_ftrace_location() { | ftrace_location() { | lookup_rec() // USE! | ftrace_release_mod() // Free! To fix this issue: 1. Hold rcu lock as accessing ftrace pages in ftrace_location_range(); 2. Use ftrace_location_range() instead of lookup_rec() in ftrace_location(); 3. Call synchronize_rcu() before freeing any ftrace pages both in ftrace_process_locs()/ftrace_release_mod()/ftrace_free_mem().

In the Linux kernel, the following vulnerability has been resolved: net: fix __dst_negative_advice() race __dst_negative_advice() does not enforce proper RCU rules when sk->dst_cache must be cleared, leading to possible UAF. RCU rules are that we must first clear sk->sk_dst_cache, then call dst_release(old_dst). Note that sk_dst_reset(sk) is implementing this protocol correctly, while __dst_negative_advice() uses the wrong order. Given that ip6_negative_advice() has special logic against RTF_CACHE, this means each of the three ->negative_advice() existing methods must perform the sk_dst_reset() themselves. Note the check against NULL dst is centralized in __dst_negative_advice(), there is no need to duplicate it in various callbacks. Many thanks to Clement Lecigne for tracking this issue. This old bug became visible after the blamed commit, using UDP sockets.