In the Linux kernel, the following vulnerability has been resolved: sfc: fix use after free when disabling sriov Use after free is detected by kfence when disabling sriov. What was read after being freed was vf->pci_dev: it was freed from pci_disable_sriov and later read in efx_ef10_sriov_free_vf_vports, called from efx_ef10_sriov_free_vf_vswitching. Set the pointer to NULL at release time to not trying to read it later. Reproducer and dmesg log (note that kfence doesn't detect it every time): $ echo 1 > /sys/class/net/enp65s0f0np0/device/sriov_numvfs $ echo 0 > /sys/class/net/enp65s0f0np0/device/sriov_numvfs BUG: KFENCE: use-after-free read in efx_ef10_sriov_free_vf_vswitching+0x82/0x170 [sfc] Use-after-free read at 0x00000000ff3c1ba5 (in kfence-#224): efx_ef10_sriov_free_vf_vswitching+0x82/0x170 [sfc] efx_ef10_pci_sriov_disable+0x38/0x70 [sfc] efx_pci_sriov_configure+0x24/0x40 [sfc] sriov_numvfs_store+0xfe/0x140 kernfs_fop_write_iter+0x11c/0x1b0 new_sync_write+0x11f/0x1b0 vfs_write+0x1eb/0x280 ksys_write+0x5f/0xe0 do_syscall_64+0x5c/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae kfence-#224: 0x00000000edb8ef95-0x00000000671f5ce1, size=2792, cache=kmalloc-4k allocated by task 6771 on cpu 10 at 3137.860196s: pci_alloc_dev+0x21/0x60 pci_iov_add_virtfn+0x2a2/0x320 sriov_enable+0x212/0x3e0 efx_ef10_sriov_configure+0x67/0x80 [sfc] efx_pci_sriov_configure+0x24/0x40 [sfc] sriov_numvfs_store+0xba/0x140 kernfs_fop_write_iter+0x11c/0x1b0 new_sync_write+0x11f/0x1b0 vfs_write+0x1eb/0x280 ksys_write+0x5f/0xe0 do_syscall_64+0x5c/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae freed by task 6771 on cpu 12 at 3170.991309s: device_release+0x34/0x90 kobject_cleanup+0x3a/0x130 pci_iov_remove_virtfn+0xd9/0x120 sriov_disable+0x30/0xe0 efx_ef10_pci_sriov_disable+0x57/0x70 [sfc] efx_pci_sriov_configure+0x24/0x40 [sfc] sriov_numvfs_store+0xfe/0x140 kernfs_fop_write_iter+0x11c/0x1b0 new_sync_write+0x11f/0x1b0 vfs_write+0x1eb/0x280 ksys_write+0x5f/0xe0 do_syscall_64+0x5c/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae

In the Linux kernel, the following vulnerability has been resolved: usbnet: Run unregister_netdev() before unbind() again Commit 2c9d6c2b871d ("usbnet: run unbind() before unregister_netdev()") sought to fix a use-after-free on disconnect of USB Ethernet adapters. It turns out that a different fix is necessary to address the issue: https://lore.kernel.org/netdev/18b3541e5372bc9b9fc733d422f4e698c089077c.1650177997.git.lukas@wunner.de/ So the commit was not necessary. The commit made binding and unbinding of USB Ethernet asymmetrical: Before, usbnet_probe() first invoked the ->bind() callback and then register_netdev(). usbnet_disconnect() mirrored that by first invoking unregister_netdev() and then ->unbind(). Since the commit, the order in usbnet_disconnect() is reversed and no longer mirrors usbnet_probe(). One consequence is that a PHY disconnected (and stopped) in ->unbind() is afterwards stopped once more by unregister_netdev() as it closes the netdev before unregistering. That necessitates a contortion in ->stop() because the PHY may only be stopped if it hasn't already been disconnected. Reverting the commit allows making the call to phy_stop() unconditional in ->stop().

In the Linux kernel, the following vulnerability has been resolved: ntfs: fix use-after-free in ntfs_attr_find() Patch series "ntfs: fix bugs about Attribute", v2. This patchset fixes three bugs relative to Attribute in record: Patch 1 adds a sanity check to ensure that, attrs_offset field in first mft record loading from disk is within bounds. Patch 2 moves the ATTR_RECORD's bounds checking earlier, to avoid dereferencing ATTR_RECORD before checking this ATTR_RECORD is within bounds. Patch 3 adds an overflow checking to avoid possible forever loop in ntfs_attr_find(). Without patch 1 and patch 2, the kernel triggersa KASAN use-after-free detection as reported by Syzkaller. Although one of patch 1 or patch 2 can fix this, we still need both of them. Because patch 1 fixes the root cause, and patch 2 not only fixes the direct cause, but also fixes the potential out-of-bounds bug. This patch (of 3): Syzkaller reported use-after-free read as follows: ================================================================== BUG: KASAN: use-after-free in ntfs_attr_find+0xc02/0xce0 fs/ntfs/attrib.c:597 Read of size 2 at addr ffff88807e352009 by task syz-executor153/3607 [...] Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 ntfs_attr_find+0xc02/0xce0 fs/ntfs/attrib.c:597 ntfs_attr_lookup+0x1056/0x2070 fs/ntfs/attrib.c:1193 ntfs_read_inode_mount+0x89a/0x2580 fs/ntfs/inode.c:1845 ntfs_fill_super+0x1799/0x9320 fs/ntfs/super.c:2854 mount_bdev+0x34d/0x410 fs/super.c:1400 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1530 do_new_mount fs/namespace.c:3040 [inline] path_mount+0x1326/0x1e20 fs/namespace.c:3370 do_mount fs/namespace.c:3383 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount fs/namespace.c:3568 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3568 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd [...] </TASK> The buggy address belongs to the physical page: page:ffffea0001f8d400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7e350 head:ffffea0001f8d400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888011842140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88807e351f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807e351f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807e352000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807e352080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807e352100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Kernel will loads $MFT/$DATA's first mft record in ntfs_read_inode_mount(). Yet the problem is that after loading, kernel doesn't check whether attrs_offset field is a valid value. To be more specific, if attrs_offset field is larger than bytes_allocated field, then it may trigger the out-of-bounds read bug(reported as use-after-free bug) in ntfs_attr_find(), when kernel tries to access the corresponding mft record's attribute. This patch solves it by adding the sanity check between attrs_offset field and bytes_allocated field, after loading the first mft record.

In the Linux kernel, the following vulnerability has been resolved: virtio-blk: Avoid use-after-free on suspend/resume hctx->user_data is set to vq in virtblk_init_hctx(). However, vq is freed on suspend and reallocated on resume. So, hctx->user_data is invalid after resume, and it will cause use-after-free accessing which will result in the kernel crash something like below: [ 22.428391] Call Trace: [ 22.428899] <TASK> [ 22.429339] virtqueue_add_split+0x3eb/0x620 [ 22.430035] ? __blk_mq_alloc_requests+0x17f/0x2d0 [ 22.430789] ? kvm_clock_get_cycles+0x14/0x30 [ 22.431496] virtqueue_add_sgs+0xad/0xd0 [ 22.432108] virtblk_add_req+0xe8/0x150 [ 22.432692] virtio_queue_rqs+0xeb/0x210 [ 22.433330] blk_mq_flush_plug_list+0x1b8/0x280 [ 22.434059] __blk_flush_plug+0xe1/0x140 [ 22.434853] blk_finish_plug+0x20/0x40 [ 22.435512] read_pages+0x20a/0x2e0 [ 22.436063] ? folio_add_lru+0x62/0xa0 [ 22.436652] page_cache_ra_unbounded+0x112/0x160 [ 22.437365] filemap_get_pages+0xe1/0x5b0 [ 22.437964] ? context_to_sid+0x70/0x100 [ 22.438580] ? sidtab_context_to_sid+0x32/0x400 [ 22.439979] filemap_read+0xcd/0x3d0 [ 22.440917] xfs_file_buffered_read+0x4a/0xc0 [ 22.441984] xfs_file_read_iter+0x65/0xd0 [ 22.442970] __kernel_read+0x160/0x2e0 [ 22.443921] bprm_execve+0x21b/0x640 [ 22.444809] do_execveat_common.isra.0+0x1a8/0x220 [ 22.446008] __x64_sys_execve+0x2d/0x40 [ 22.446920] do_syscall_64+0x37/0x90 [ 22.447773] entry_SYSCALL_64_after_hwframe+0x63/0xcd This patch fixes this issue by getting vq from vblk, and removes virtblk_init_hctx().

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: Fix use after free in hci_send_acl This fixes the following trace caused by receiving HCI_EV_DISCONN_PHY_LINK_COMPLETE which does call hci_conn_del without first checking if conn->type is in fact AMP_LINK and in case it is do properly cleanup upper layers with hci_disconn_cfm: ================================================================== BUG: KASAN: use-after-free in hci_send_acl+0xaba/0xc50 Read of size 8 at addr ffff88800e404818 by task bluetoothd/142 CPU: 0 PID: 142 Comm: bluetoothd Not tainted 5.17.0-rc5-00006-gda4022eeac1a #7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x45/0x59 print_address_description.constprop.0+0x1f/0x150 kasan_report.cold+0x7f/0x11b hci_send_acl+0xaba/0xc50 l2cap_do_send+0x23f/0x3d0 l2cap_chan_send+0xc06/0x2cc0 l2cap_sock_sendmsg+0x201/0x2b0 sock_sendmsg+0xdc/0x110 sock_write_iter+0x20f/0x370 do_iter_readv_writev+0x343/0x690 do_iter_write+0x132/0x640 vfs_writev+0x198/0x570 do_writev+0x202/0x280 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RSP: 002b:00007ffce8a099b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 Code: 0f 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 14 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10 RDX: 0000000000000001 RSI: 00007ffce8a099e0 RDI: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffce8a099e0 RCX: 00007f788fc3cf77 R10: 00007ffce8af7080 R11: 0000000000000246 R12: 000055e4ccf75580 RBP: 0000000000000015 R08: 0000000000000002 R09: 0000000000000001 </TASK> R13: 000055e4ccf754a0 R14: 000055e4ccf75cd0 R15: 000055e4ccf4a6b0 Allocated by task 45: kasan_save_stack+0x1e/0x40 __kasan_kmalloc+0x81/0xa0 hci_chan_create+0x9a/0x2f0 l2cap_conn_add.part.0+0x1a/0xdc0 l2cap_connect_cfm+0x236/0x1000 le_conn_complete_evt+0x15a7/0x1db0 hci_le_conn_complete_evt+0x226/0x2c0 hci_le_meta_evt+0x247/0x450 hci_event_packet+0x61b/0xe90 hci_rx_work+0x4d5/0xc50 process_one_work+0x8fb/0x15a0 worker_thread+0x576/0x1240 kthread+0x29d/0x340 ret_from_fork+0x1f/0x30 Freed by task 45: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_set_free_info+0x20/0x30 __kasan_slab_free+0xfb/0x130 kfree+0xac/0x350 hci_conn_cleanup+0x101/0x6a0 hci_conn_del+0x27e/0x6c0 hci_disconn_phylink_complete_evt+0xe0/0x120 hci_event_packet+0x812/0xe90 hci_rx_work+0x4d5/0xc50 process_one_work+0x8fb/0x15a0 worker_thread+0x576/0x1240 kthread+0x29d/0x340 ret_from_fork+0x1f/0x30 The buggy address belongs to the object at ffff88800c0f0500 The buggy address is located 24 bytes inside of which belongs to the cache kmalloc-128 of size 128 The buggy address belongs to the page: 128-byte region [ffff88800c0f0500, ffff88800c0f0580) flags: 0x100000000000200(slab|node=0|zone=1) page:00000000fe45cd86 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xc0f0 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 raw: 0100000000000200 ffffea00003a2c80 dead000000000004 ffff8880078418c0 page dumped because: kasan: bad access detected ffff88800c0f0400: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc Memory state around the buggy address: >ffff88800c0f0500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88800c0f0480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88800c0f0580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ---truncated---

In the Linux kernel, the following vulnerability has been resolved: bnxt: prevent skb UAF after handing over to PTP worker When reading the timestamp is required bnxt_tx_int() hands over the ownership of the completed skb to the PTP worker. The skb should not be used afterwards, as the worker may run before the rest of our code and free the skb, leading to a use-after-free. Since dev_kfree_skb_any() accepts NULL make the loss of ownership more obvious and set skb to NULL.

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Fix races among concurrent prealloc proc writes We have no protection against concurrent PCM buffer preallocation changes via proc files, and it may potentially lead to UAF or some weird problem. This patch applies the PCM open_mutex to the proc write operation for avoiding the racy proc writes and the PCM stream open (and further operations).

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Fix races among concurrent hw_params and hw_free calls Currently we have neither proper check nor protection against the concurrent calls of PCM hw_params and hw_free ioctls, which may result in a UAF. Since the existing PCM stream lock can't be used for protecting the whole ioctl operations, we need a new mutex to protect those racy calls. This patch introduced a new mutex, runtime->buffer_mutex, and applies it to both hw_params and hw_free ioctl code paths. Along with it, the both functions are slightly modified (the mmap_count check is moved into the state-check block) for code simplicity.

In the Linux kernel, the following vulnerability has been resolved: can: m_can: m_can_tx_handler(): fix use after free of skb can_put_echo_skb() will clone skb then free the skb. Move the can_put_echo_skb() for the m_can version 3.0.x directly before the start of the xmit in hardware, similar to the 3.1.x branch.

In the Linux kernel, the following vulnerability has been resolved: scsi: target: tcmu: Fix possible page UAF tcmu_try_get_data_page() looks up pages under cmdr_lock, but it does not take refcount properly and just returns page pointer. When tcmu_try_get_data_page() returns, the returned page may have been freed by tcmu_blocks_release(). We need to get_page() under cmdr_lock to avoid concurrent tcmu_blocks_release().

In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: Prevent use after free on completion memory On driver unload any pending descriptors are flushed at the time the interrupt is freed: idxd_dmaengine_drv_remove() -> drv_disable_wq() -> idxd_wq_free_irq() -> idxd_flush_pending_descs(). If there are any descriptors present that need to be flushed this flow triggers a "not present" page fault as below: BUG: unable to handle page fault for address: ff391c97c70c9040 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page The address that triggers the fault is the address of the descriptor that was freed moments earlier via: drv_disable_wq()->idxd_wq_free_resources() Fix the use after free by freeing the descriptors after any possible usage. This is done after idxd_wq_reset() to ensure that the memory remains accessible during possible completion writes by the device.

In the Linux kernel, the following vulnerability has been resolved: ep93xx: clock: Fix UAF in ep93xx_clk_register_gate() arch/arm/mach-ep93xx/clock.c:154:2: warning: Use of memory after it is freed [clang-analyzer-unix.Malloc] arch/arm/mach-ep93xx/clock.c:151:2: note: Taking true branch if (IS_ERR(clk)) ^ arch/arm/mach-ep93xx/clock.c:152:3: note: Memory is released kfree(psc); ^~~~~~~~~~ arch/arm/mach-ep93xx/clock.c:154:2: note: Use of memory after it is freed return &psc->hw; ^ ~~~~~~~~

In the Linux kernel, the following vulnerability has been resolved: iommu: Fix potential use-after-free during probe Kasan has reported the following use after free on dev->iommu. when a device probe fails and it is in process of freeing dev->iommu in dev_iommu_free function, a deferred_probe_work_func runs in parallel and tries to access dev->iommu->fwspec in of_iommu_configure path thus causing use after free. BUG: KASAN: use-after-free in of_iommu_configure+0xb4/0x4a4 Read of size 8 at addr ffffff87a2f1acb8 by task kworker/u16:2/153 Workqueue: events_unbound deferred_probe_work_func Call trace: dump_backtrace+0x0/0x33c show_stack+0x18/0x24 dump_stack_lvl+0x16c/0x1e0 print_address_description+0x84/0x39c __kasan_report+0x184/0x308 kasan_report+0x50/0x78 __asan_load8+0xc0/0xc4 of_iommu_configure+0xb4/0x4a4 of_dma_configure_id+0x2fc/0x4d4 platform_dma_configure+0x40/0x5c really_probe+0x1b4/0xb74 driver_probe_device+0x11c/0x228 __device_attach_driver+0x14c/0x304 bus_for_each_drv+0x124/0x1b0 __device_attach+0x25c/0x334 device_initial_probe+0x24/0x34 bus_probe_device+0x78/0x134 deferred_probe_work_func+0x130/0x1a8 process_one_work+0x4c8/0x970 worker_thread+0x5c8/0xaec kthread+0x1f8/0x220 ret_from_fork+0x10/0x18 Allocated by task 1: ____kasan_kmalloc+0xd4/0x114 __kasan_kmalloc+0x10/0x1c kmem_cache_alloc_trace+0xe4/0x3d4 __iommu_probe_device+0x90/0x394 probe_iommu_group+0x70/0x9c bus_for_each_dev+0x11c/0x19c bus_iommu_probe+0xb8/0x7d4 bus_set_iommu+0xcc/0x13c arm_smmu_bus_init+0x44/0x130 [arm_smmu] arm_smmu_device_probe+0xb88/0xc54 [arm_smmu] platform_drv_probe+0xe4/0x13c really_probe+0x2c8/0xb74 driver_probe_device+0x11c/0x228 device_driver_attach+0xf0/0x16c __driver_attach+0x80/0x320 bus_for_each_dev+0x11c/0x19c driver_attach+0x38/0x48 bus_add_driver+0x1dc/0x3a4 driver_register+0x18c/0x244 __platform_driver_register+0x88/0x9c init_module+0x64/0xff4 [arm_smmu] do_one_initcall+0x17c/0x2f0 do_init_module+0xe8/0x378 load_module+0x3f80/0x4a40 __se_sys_finit_module+0x1a0/0x1e4 __arm64_sys_finit_module+0x44/0x58 el0_svc_common+0x100/0x264 do_el0_svc+0x38/0xa4 el0_svc+0x20/0x30 el0_sync_handler+0x68/0xac el0_sync+0x160/0x180 Freed by task 1: kasan_set_track+0x4c/0x84 kasan_set_free_info+0x28/0x4c ____kasan_slab_free+0x120/0x15c __kasan_slab_free+0x18/0x28 slab_free_freelist_hook+0x204/0x2fc kfree+0xfc/0x3a4 __iommu_probe_device+0x284/0x394 probe_iommu_group+0x70/0x9c bus_for_each_dev+0x11c/0x19c bus_iommu_probe+0xb8/0x7d4 bus_set_iommu+0xcc/0x13c arm_smmu_bus_init+0x44/0x130 [arm_smmu] arm_smmu_device_probe+0xb88/0xc54 [arm_smmu] platform_drv_probe+0xe4/0x13c really_probe+0x2c8/0xb74 driver_probe_device+0x11c/0x228 device_driver_attach+0xf0/0x16c __driver_attach+0x80/0x320 bus_for_each_dev+0x11c/0x19c driver_attach+0x38/0x48 bus_add_driver+0x1dc/0x3a4 driver_register+0x18c/0x244 __platform_driver_register+0x88/0x9c init_module+0x64/0xff4 [arm_smmu] do_one_initcall+0x17c/0x2f0 do_init_module+0xe8/0x378 load_module+0x3f80/0x4a40 __se_sys_finit_module+0x1a0/0x1e4 __arm64_sys_finit_module+0x44/0x58 el0_svc_common+0x100/0x264 do_el0_svc+0x38/0xa4 el0_svc+0x20/0x30 el0_sync_handler+0x68/0xac el0_sync+0x160/0x180 Fix this by setting dev->iommu to NULL first and then freeing dev_iommu structure in dev_iommu_free function.

In the Linux kernel, the following vulnerability has been resolved: scsi: mpt3sas: Fix use-after-free warning Fix the following use-after-free warning which is observed during controller reset: refcount_t: underflow; use-after-free. WARNING: CPU: 23 PID: 5399 at lib/refcount.c:28 refcount_warn_saturate+0xa6/0xf0

In the Linux kernel, the following vulnerability has been resolved: scsi: libfc: Fix use after free in fc_exch_abts_resp() fc_exch_release(ep) will decrease the ep's reference count. When the reference count reaches zero, it is freed. But ep is still used in the following code, which will lead to a use after free. Return after the fc_exch_release() call to avoid use after free.

In the Linux kernel, the following vulnerability has been resolved: crypto: ccree - Fix use after free in cc_cipher_exit() kfree_sensitive(ctx_p->user.key) will free the ctx_p->user.key. But ctx_p->user.key is still used in the next line, which will lead to a use after free. We can call kfree_sensitive() after dev_dbg() to avoid the uaf.

In the Linux kernel, the following vulnerability has been resolved: mm/slab_common: fix possible double free of kmem_cache When doing slub_debug test, kfence's 'test_memcache_typesafe_by_rcu' kunit test case cause a use-after-free error: BUG: KASAN: use-after-free in kobject_del+0x14/0x30 Read of size 8 at addr ffff888007679090 by task kunit_try_catch/261 CPU: 1 PID: 261 Comm: kunit_try_catch Tainted: G B N 6.0.0-rc5-next-20220916 #17 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x34/0x48 print_address_description.constprop.0+0x87/0x2a5 print_report+0x103/0x1ed kasan_report+0xb7/0x140 kobject_del+0x14/0x30 kmem_cache_destroy+0x130/0x170 test_exit+0x1a/0x30 kunit_try_run_case+0xad/0xc0 kunit_generic_run_threadfn_adapter+0x26/0x50 kthread+0x17b/0x1b0 </TASK> The cause is inside kmem_cache_destroy(): kmem_cache_destroy acquire lock/mutex shutdown_cache schedule_work(kmem_cache_release) (if RCU flag set) release lock/mutex kmem_cache_release (if RCU flag not set) In some certain timing, the scheduled work could be run before the next RCU flag checking, which can then get a wrong value and lead to double kmem_cache_release(). Fix it by caching the RCU flag inside protected area, just like 'refcnt'

In the Linux kernel, the following vulnerability has been resolved: btrfs: do not clean up repair bio if submit fails The submit helper will always run bio_endio() on the bio if it fails to submit, so cleaning up the bio just leads to a variety of use-after-free and NULL pointer dereference bugs because we race with the endio function that is cleaning up the bio. Instead just return BLK_STS_OK as the repair function has to continue to process the rest of the pages, and the endio for the repair bio will do the appropriate cleanup for the page that it was given.

In the Linux kernel, the following vulnerability has been resolved: tipc: re-fetch skb cb after tipc_msg_validate As the call trace shows, the original skb was freed in tipc_msg_validate(), and dereferencing the old skb cb would cause an use-after-free crash. BUG: KASAN: use-after-free in tipc_crypto_rcv_complete+0x1835/0x2240 [tipc] Call Trace: <IRQ> tipc_crypto_rcv_complete+0x1835/0x2240 [tipc] tipc_crypto_rcv+0xd32/0x1ec0 [tipc] tipc_rcv+0x744/0x1150 [tipc] ... Allocated by task 47078: kmem_cache_alloc_node+0x158/0x4d0 __alloc_skb+0x1c1/0x270 tipc_buf_acquire+0x1e/0xe0 [tipc] tipc_msg_create+0x33/0x1c0 [tipc] tipc_link_build_proto_msg+0x38a/0x2100 [tipc] tipc_link_timeout+0x8b8/0xef0 [tipc] tipc_node_timeout+0x2a1/0x960 [tipc] call_timer_fn+0x2d/0x1c0 ... Freed by task 47078: tipc_msg_validate+0x7b/0x440 [tipc] tipc_crypto_rcv_complete+0x4b5/0x2240 [tipc] tipc_crypto_rcv+0xd32/0x1ec0 [tipc] tipc_rcv+0x744/0x1150 [tipc] This patch fixes it by re-fetching the skb cb from the new allocated skb after calling tipc_msg_validate().

In the Linux kernel, the following vulnerability has been resolved: s390/qeth: fix use-after-free in hsci KASAN found that addr was dereferenced after br2dev_event_work was freed. ================================================================== BUG: KASAN: use-after-free in qeth_l2_br2dev_worker+0x5ba/0x6b0 Read of size 1 at addr 00000000fdcea440 by task kworker/u760:4/540 CPU: 17 PID: 540 Comm: kworker/u760:4 Tainted: G E 6.1.0-20221128.rc7.git1.5aa3bed4ce83.300.fc36.s390x+kasan #1 Hardware name: IBM 8561 T01 703 (LPAR) Workqueue: 0.0.8000_event qeth_l2_br2dev_worker Call Trace: [<000000016944d4ce>] dump_stack_lvl+0xc6/0xf8 [<000000016942cd9c>] print_address_description.constprop.0+0x34/0x2a0 [<000000016942d118>] print_report+0x110/0x1f8 [<0000000167a7bd04>] kasan_report+0xfc/0x128 [<000000016938d79a>] qeth_l2_br2dev_worker+0x5ba/0x6b0 [<00000001673edd1e>] process_one_work+0x76e/0x1128 [<00000001673ee85c>] worker_thread+0x184/0x1098 [<000000016740718a>] kthread+0x26a/0x310 [<00000001672c606a>] __ret_from_fork+0x8a/0xe8 [<00000001694711da>] ret_from_fork+0xa/0x40 Allocated by task 108338: kasan_save_stack+0x40/0x68 kasan_set_track+0x36/0x48 __kasan_kmalloc+0xa0/0xc0 qeth_l2_switchdev_event+0x25a/0x738 atomic_notifier_call_chain+0x9c/0xf8 br_switchdev_fdb_notify+0xf4/0x110 fdb_notify+0x122/0x180 fdb_add_entry.constprop.0.isra.0+0x312/0x558 br_fdb_add+0x59e/0x858 rtnl_fdb_add+0x58a/0x928 rtnetlink_rcv_msg+0x5f8/0x8d8 netlink_rcv_skb+0x1f2/0x408 netlink_unicast+0x570/0x790 netlink_sendmsg+0x752/0xbe0 sock_sendmsg+0xca/0x110 ____sys_sendmsg+0x510/0x6a8 ___sys_sendmsg+0x12a/0x180 __sys_sendmsg+0xe6/0x168 __do_sys_socketcall+0x3c8/0x468 do_syscall+0x22c/0x328 __do_syscall+0x94/0xf0 system_call+0x82/0xb0 Freed by task 540: kasan_save_stack+0x40/0x68 kasan_set_track+0x36/0x48 kasan_save_free_info+0x4c/0x68 ____kasan_slab_free+0x14e/0x1a8 __kasan_slab_free+0x24/0x30 __kmem_cache_free+0x168/0x338 qeth_l2_br2dev_worker+0x154/0x6b0 process_one_work+0x76e/0x1128 worker_thread+0x184/0x1098 kthread+0x26a/0x310 __ret_from_fork+0x8a/0xe8 ret_from_fork+0xa/0x40 Last potentially related work creation: kasan_save_stack+0x40/0x68 __kasan_record_aux_stack+0xbe/0xd0 insert_work+0x56/0x2e8 __queue_work+0x4ce/0xd10 queue_work_on+0xf4/0x100 qeth_l2_switchdev_event+0x520/0x738 atomic_notifier_call_chain+0x9c/0xf8 br_switchdev_fdb_notify+0xf4/0x110 fdb_notify+0x122/0x180 fdb_add_entry.constprop.0.isra.0+0x312/0x558 br_fdb_add+0x59e/0x858 rtnl_fdb_add+0x58a/0x928 rtnetlink_rcv_msg+0x5f8/0x8d8 netlink_rcv_skb+0x1f2/0x408 netlink_unicast+0x570/0x790 netlink_sendmsg+0x752/0xbe0 sock_sendmsg+0xca/0x110 ____sys_sendmsg+0x510/0x6a8 ___sys_sendmsg+0x12a/0x180 __sys_sendmsg+0xe6/0x168 __do_sys_socketcall+0x3c8/0x468 do_syscall+0x22c/0x328 __do_syscall+0x94/0xf0 system_call+0x82/0xb0 Second to last potentially related work creation: kasan_save_stack+0x40/0x68 __kasan_record_aux_stack+0xbe/0xd0 kvfree_call_rcu+0xb2/0x760 kernfs_unlink_open_file+0x348/0x430 kernfs_fop_release+0xc2/0x320 __fput+0x1ae/0x768 task_work_run+0x1bc/0x298 exit_to_user_mode_prepare+0x1a0/0x1a8 __do_syscall+0x94/0xf0 system_call+0x82/0xb0 The buggy address belongs to the object at 00000000fdcea400 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 64 bytes inside of 96-byte region [00000000fdcea400, 00000000fdcea460) The buggy address belongs to the physical page: page:000000005a9c26e8 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xfdcea flags: 0x3ffff00000000200(slab|node=0|zone=1|lastcpupid=0x1ffff) raw: 3ffff00000000200 0000000000000000 0000000100000122 000000008008cc00 raw: 0000000000000000 0020004100000000 ffffffff00000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: 00000000fdcea300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc 00000000fdcea380: fb fb fb fb fb fb f ---truncated---

In the Linux kernel, the following vulnerability has been resolved: mt76: mt7921: fix crash when startup fails. If the nic fails to start, it is possible that the reset_work has already been scheduled. Ensure the work item is canceled so we do not have use-after-free crash in case cleanup is called before the work item is executed. This fixes crash on my x86_64 apu2 when mt7921k radio fails to work. Radio still fails, but OS does not crash.

In the Linux kernel, the following vulnerability has been resolved: net: hisilicon: Fix potential use-after-free in hix5hd2_rx() The skb is delivered to napi_gro_receive() which may free it, after calling this, dereferencing skb may trigger use-after-free.

In the Linux kernel, the following vulnerability has been resolved: net: hsr: Fix potential use-after-free The skb is delivered to netif_rx() which may free it, after calling this, dereferencing skb may trigger use-after-free.

In the Linux kernel, the following vulnerability has been resolved: mm/khugepaged: invoke MMU notifiers in shmem/file collapse paths Any codepath that zaps page table entries must invoke MMU notifiers to ensure that secondary MMUs (like KVM) don't keep accessing pages which aren't mapped anymore. Secondary MMUs don't hold their own references to pages that are mirrored over, so failing to notify them can lead to page use-after-free. I'm marking this as addressing an issue introduced in commit f3f0e1d2150b ("khugepaged: add support of collapse for tmpfs/shmem pages"), but most of the security impact of this only came in commit 27e1f8273113 ("khugepaged: enable collapse pmd for pte-mapped THP"), which actually omitted flushes for the removal of present PTEs, not just for the removal of empty page tables.

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: avoid double fput() on failed usercopy If the copy back to userland fails for the FASTRPC_IOCTL_ALLOC_DMA_BUFF ioctl(), we shouldn't assume that 'buf->dmabuf' is still valid. In fact, dma_buf_fd() called fd_install() before, i.e. "consumed" one reference, leaving us with none. Calling dma_buf_put() will therefore put a reference we no longer own, leading to a valid file descritor table entry for an already released 'file' object which is a straight use-after-free. Simply avoid calling dma_buf_put() and rely on the process exit code to do the necessary cleanup, if needed, i.e. if the file descriptor is still valid.

In the Linux kernel, the following vulnerability has been resolved: drm/shmem-helper: Remove errant put in error path drm_gem_shmem_mmap() doesn't own this reference, resulting in the GEM object getting prematurely freed leading to a later use-after-free.

In the Linux kernel, the following vulnerability has been resolved: scsi: pm8001: Fix use-after-free for aborted TMF sas_task Currently a use-after-free may occur if a TMF sas_task is aborted before we handle the IO completion in mpi_ssp_completion(). The abort occurs due to timeout. When the timeout occurs, the SAS_TASK_STATE_ABORTED flag is set and the sas_task is freed in pm8001_exec_internal_tmf_task(). However, if the I/O completion occurs later, the I/O completion still thinks that the sas_task is available. Fix this by clearing the ccb->task if the TMF times out - the I/O completion handler does nothing if this pointer is cleared.

In the Linux kernel, the following vulnerability has been resolved: iio: buffer: Fix file related error handling in IIO_BUFFER_GET_FD_IOCTL If we fail to copy the just created file descriptor to userland, we try to clean up by putting back 'fd' and freeing 'ib'. The code uses put_unused_fd() for the former which is wrong, as the file descriptor was already published by fd_install() which gets called internally by anon_inode_getfd(). This makes the error handling code leaving a half cleaned up file descriptor table around and a partially destructed 'file' object, allowing userland to play use-after-free tricks on us, by abusing the still usable fd and making the code operate on a dangling 'file->private_data' pointer. Instead of leaving the kernel in a partially corrupted state, don't attempt to explicitly clean up and leave this to the process exit path that'll release any still valid fds, including the one created by the previous call to anon_inode_getfd(). Simply return -EFAULT to indicate the error.

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: RDMA/ucma: Protect mc during concurrent multicast leaves Partially revert the commit mentioned in the Fixes line to make sure that allocation and erasing multicast struct are locked. BUG: KASAN: use-after-free in ucma_cleanup_multicast drivers/infiniband/core/ucma.c:491 [inline] BUG: KASAN: use-after-free in ucma_destroy_private_ctx+0x914/0xb70 drivers/infiniband/core/ucma.c:579 Read of size 8 at addr ffff88801bb74b00 by task syz-executor.1/25529 CPU: 0 PID: 25529 Comm: syz-executor.1 Not tainted 5.16.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x320 mm/kasan/report.c:247 __kasan_report mm/kasan/report.c:433 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:450 ucma_cleanup_multicast drivers/infiniband/core/ucma.c:491 [inline] ucma_destroy_private_ctx+0x914/0xb70 drivers/infiniband/core/ucma.c:579 ucma_destroy_id+0x1e6/0x280 drivers/infiniband/core/ucma.c:614 ucma_write+0x25c/0x350 drivers/infiniband/core/ucma.c:1732 vfs_write+0x28e/0xae0 fs/read_write.c:588 ksys_write+0x1ee/0x250 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Currently the xarray search can touch a concurrently freeing mc as the xa_for_each() is not surrounded by any lock. Rather than hold the lock for a full scan hold it only for the effected items, which is usually an empty list.

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: ext4: fix use-after-free in ext4_rename_dir_prepare We got issue as follows: EXT4-fs (loop0): mounted filesystem without journal. Opts: ,errors=continue ext4_get_first_dir_block: bh->b_data=0xffff88810bee6000 len=34478 ext4_get_first_dir_block: *parent_de=0xffff88810beee6ae bh->b_data=0xffff88810bee6000 ext4_rename_dir_prepare: [1] parent_de=0xffff88810beee6ae ================================================================== BUG: KASAN: use-after-free in ext4_rename_dir_prepare+0x152/0x220 Read of size 4 at addr ffff88810beee6ae by task rep/1895 CPU: 13 PID: 1895 Comm: rep Not tainted 5.10.0+ #241 Call Trace: dump_stack+0xbe/0xf9 print_address_description.constprop.0+0x1e/0x220 kasan_report.cold+0x37/0x7f ext4_rename_dir_prepare+0x152/0x220 ext4_rename+0xf44/0x1ad0 ext4_rename2+0x11c/0x170 vfs_rename+0xa84/0x1440 do_renameat2+0x683/0x8f0 __x64_sys_renameat+0x53/0x60 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f45a6fc41c9 RSP: 002b:00007ffc5a470218 EFLAGS: 00000246 ORIG_RAX: 0000000000000108 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f45a6fc41c9 RDX: 0000000000000005 RSI: 0000000020000180 RDI: 0000000000000005 RBP: 00007ffc5a470240 R08: 00007ffc5a470160 R09: 0000000020000080 R10: 00000000200001c0 R11: 0000000000000246 R12: 0000000000400bb0 R13: 00007ffc5a470320 R14: 0000000000000000 R15: 0000000000000000 The buggy address belongs to the page: page:00000000440015ce refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x10beee flags: 0x200000000000000() raw: 0200000000000000 ffffea00043ff4c8 ffffea0004325608 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88810beee580: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88810beee600: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88810beee680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88810beee700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88810beee780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== Disabling lock debugging due to kernel taint ext4_rename_dir_prepare: [2] parent_de->inode=3537895424 ext4_rename_dir_prepare: [3] dir=0xffff888124170140 ext4_rename_dir_prepare: [4] ino=2 ext4_rename_dir_prepare: ent->dir->i_ino=2 parent=-757071872 Reason is first directory entry which 'rec_len' is 34478, then will get illegal parent entry. Now, we do not check directory entry after read directory block in 'ext4_get_first_dir_block'. To solve this issue, check directory entry in 'ext4_get_first_dir_block'. [ Trigger an ext4_error() instead of just warning if the directory is missing a '.' or '..' entry. Also make sure we return an error code if the file system is corrupted. -TYT ]

In the Linux kernel, the following vulnerability has been resolved: mctp: fix use after free Clang static analysis reports this problem route.c:425:4: warning: Use of memory after it is freed trace_mctp_key_acquire(key); ^~~~~~~~~~~~~~~~~~~~~~~~~~~ When mctp_key_add() fails, key is freed but then is later used in trace_mctp_key_acquire(). Add an else statement to use the key only when mctp_key_add() is successful.

In the Linux kernel, the following vulnerability has been resolved: ice: arfs: fix use-after-free when freeing @rx_cpu_rmap The CI testing bots triggered the following splat: [ 718.203054] BUG: KASAN: use-after-free in free_irq_cpu_rmap+0x53/0x80 [ 718.206349] Read of size 4 at addr ffff8881bd127e00 by task sh/20834 [ 718.212852] CPU: 28 PID: 20834 Comm: sh Kdump: loaded Tainted: G S W IOE 5.17.0-rc8_nextqueue-devqueue-02643-g23f3121aca93 #1 [ 718.219695] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0012.070720200218 07/07/2020 [ 718.223418] Call Trace: [ 718.227139] [ 718.230783] dump_stack_lvl+0x33/0x42 [ 718.234431] print_address_description.constprop.9+0x21/0x170 [ 718.238177] ? free_irq_cpu_rmap+0x53/0x80 [ 718.241885] ? free_irq_cpu_rmap+0x53/0x80 [ 718.245539] kasan_report.cold.18+0x7f/0x11b [ 718.249197] ? free_irq_cpu_rmap+0x53/0x80 [ 718.252852] free_irq_cpu_rmap+0x53/0x80 [ 718.256471] ice_free_cpu_rx_rmap.part.11+0x37/0x50 [ice] [ 718.260174] ice_remove_arfs+0x5f/0x70 [ice] [ 718.263810] ice_rebuild_arfs+0x3b/0x70 [ice] [ 718.267419] ice_rebuild+0x39c/0xb60 [ice] [ 718.270974] ? asm_sysvec_apic_timer_interrupt+0x12/0x20 [ 718.274472] ? ice_init_phy_user_cfg+0x360/0x360 [ice] [ 718.278033] ? delay_tsc+0x4a/0xb0 [ 718.281513] ? preempt_count_sub+0x14/0xc0 [ 718.284984] ? delay_tsc+0x8f/0xb0 [ 718.288463] ice_do_reset+0x92/0xf0 [ice] [ 718.292014] ice_pci_err_resume+0x91/0xf0 [ice] [ 718.295561] pci_reset_function+0x53/0x80 <...> [ 718.393035] Allocated by task 690: [ 718.433497] Freed by task 20834: [ 718.495688] Last potentially related work creation: [ 718.568966] The buggy address belongs to the object at ffff8881bd127e00 which belongs to the cache kmalloc-96 of size 96 [ 718.574085] The buggy address is located 0 bytes inside of 96-byte region [ffff8881bd127e00, ffff8881bd127e60) [ 718.579265] The buggy address belongs to the page: [ 718.598905] Memory state around the buggy address: [ 718.601809] ffff8881bd127d00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 718.604796] ffff8881bd127d80: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc [ 718.607794] >ffff8881bd127e00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc [ 718.610811] ^ [ 718.613819] ffff8881bd127e80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 718.617107] ffff8881bd127f00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc This is due to that free_irq_cpu_rmap() is always being called *after* (devm_)free_irq() and thus it tries to work with IRQ descs already freed. For example, on device reset the driver frees the rmap right before allocating a new one (the splat above). Make rmap creation and freeing function symmetrical with {request,free}_irq() calls i.e. do that on ifup/ifdown instead of device probe/remove/resume. These operations can be performed independently from the actual device aRFS configuration. Also, make sure ice_vsi_free_irq() clears IRQ affinity notifiers only when aRFS is disabled -- otherwise, CPU rmap sets and clears its own and they must not be touched manually.

In the Linux kernel, the following vulnerability has been resolved: net: hisilicon: Fix potential use-after-free in hisi_femac_rx() The skb is delivered to napi_gro_receive() which may free it, after calling this, dereferencing skb may trigger use-after-free.

In the Linux kernel, the following vulnerability has been resolved: nfc: nci: add flush_workqueue to prevent uaf Our detector found a concurrent use-after-free bug when detaching an NCI device. The main reason for this bug is the unexpected scheduling between the used delayed mechanism (timer and workqueue). The race can be demonstrated below: Thread-1 Thread-2 | nci_dev_up() | nci_open_device() | __nci_request(nci_reset_req) | nci_send_cmd | queue_work(cmd_work) nci_unregister_device() | nci_close_device() | ... del_timer_sync(cmd_timer)[1] | ... | Worker nci_free_device() | nci_cmd_work() kfree(ndev)[3] | mod_timer(cmd_timer)[2] In short, the cleanup routine thought that the cmd_timer has already been detached by [1] but the mod_timer can re-attach the timer [2], even it is already released [3], resulting in UAF. This UAF is easy to trigger, crash trace by POC is like below [ 66.703713] ================================================================== [ 66.703974] BUG: KASAN: use-after-free in enqueue_timer+0x448/0x490 [ 66.703974] Write of size 8 at addr ffff888009fb7058 by task kworker/u4:1/33 [ 66.703974] [ 66.703974] CPU: 1 PID: 33 Comm: kworker/u4:1 Not tainted 5.18.0-rc2 #5 [ 66.703974] Workqueue: nfc2_nci_cmd_wq nci_cmd_work [ 66.703974] Call Trace: [ 66.703974] <TASK> [ 66.703974] dump_stack_lvl+0x57/0x7d [ 66.703974] print_report.cold+0x5e/0x5db [ 66.703974] ? enqueue_timer+0x448/0x490 [ 66.703974] kasan_report+0xbe/0x1c0 [ 66.703974] ? enqueue_timer+0x448/0x490 [ 66.703974] enqueue_timer+0x448/0x490 [ 66.703974] __mod_timer+0x5e6/0xb80 [ 66.703974] ? mark_held_locks+0x9e/0xe0 [ 66.703974] ? try_to_del_timer_sync+0xf0/0xf0 [ 66.703974] ? lockdep_hardirqs_on_prepare+0x17b/0x410 [ 66.703974] ? queue_work_on+0x61/0x80 [ 66.703974] ? lockdep_hardirqs_on+0xbf/0x130 [ 66.703974] process_one_work+0x8bb/0x1510 [ 66.703974] ? lockdep_hardirqs_on_prepare+0x410/0x410 [ 66.703974] ? pwq_dec_nr_in_flight+0x230/0x230 [ 66.703974] ? rwlock_bug.part.0+0x90/0x90 [ 66.703974] ? _raw_spin_lock_irq+0x41/0x50 [ 66.703974] worker_thread+0x575/0x1190 [ 66.703974] ? process_one_work+0x1510/0x1510 [ 66.703974] kthread+0x2a0/0x340 [ 66.703974] ? kthread_complete_and_exit+0x20/0x20 [ 66.703974] ret_from_fork+0x22/0x30 [ 66.703974] </TASK> [ 66.703974] [ 66.703974] Allocated by task 267: [ 66.703974] kasan_save_stack+0x1e/0x40 [ 66.703974] __kasan_kmalloc+0x81/0xa0 [ 66.703974] nci_allocate_device+0xd3/0x390 [ 66.703974] nfcmrvl_nci_register_dev+0x183/0x2c0 [ 66.703974] nfcmrvl_nci_uart_open+0xf2/0x1dd [ 66.703974] nci_uart_tty_ioctl+0x2c3/0x4a0 [ 66.703974] tty_ioctl+0x764/0x1310 [ 66.703974] __x64_sys_ioctl+0x122/0x190 [ 66.703974] do_syscall_64+0x3b/0x90 [ 66.703974] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 66.703974] [ 66.703974] Freed by task 406: [ 66.703974] kasan_save_stack+0x1e/0x40 [ 66.703974] kasan_set_track+0x21/0x30 [ 66.703974] kasan_set_free_info+0x20/0x30 [ 66.703974] __kasan_slab_free+0x108/0x170 [ 66.703974] kfree+0xb0/0x330 [ 66.703974] nfcmrvl_nci_unregister_dev+0x90/0xd0 [ 66.703974] nci_uart_tty_close+0xdf/0x180 [ 66.703974] tty_ldisc_kill+0x73/0x110 [ 66.703974] tty_ldisc_hangup+0x281/0x5b0 [ 66.703974] __tty_hangup.part.0+0x431/0x890 [ 66.703974] tty_release+0x3a8/0xc80 [ 66.703974] __fput+0x1f0/0x8c0 [ 66.703974] task_work_run+0xc9/0x170 [ 66.703974] exit_to_user_mode_prepare+0x194/0x1a0 [ 66.703974] syscall_exit_to_user_mode+0x19/0x50 [ 66.703974] do_syscall_64+0x48/0x90 [ 66.703974] entry_SYSCALL_64_after_hwframe+0x44/0x ---truncated---

In the Linux kernel, the following vulnerability has been resolved: RDMA/hfi1: Fix use-after-free bug for mm struct Under certain conditions, such as MPI_Abort, the hfi1 cleanup code may represent the last reference held on the task mm. hfi1_mmu_rb_unregister() then drops the last reference and the mm is freed before the final use in hfi1_release_user_pages(). A new task may allocate the mm structure while it is still being used, resulting in problems. One manifestation is corruption of the mmap_sem counter leading to a hang in down_write(). Another is corruption of an mm struct that is in use by another task.

In the Linux kernel, the following vulnerability has been resolved: rtnetlink: make sure to refresh master_dev/m_ops in __rtnl_newlink() While looking at one unrelated syzbot bug, I found the replay logic in __rtnl_newlink() to potentially trigger use-after-free. It is better to clear master_dev and m_ops inside the loop, in case we have to replay it.

In the Linux kernel, the following vulnerability has been resolved: net: hns3: add vlan list lock to protect vlan list When adding port base VLAN, vf VLAN need to remove from HW and modify the vlan state in vf VLAN list as false. If the periodicity task is freeing the same node, it may cause "use after free" error. This patch adds a vlan list lock to protect the vlan list.

In the Linux kernel, the following vulnerability has been resolved: ravb: Fix potential use-after-free in ravb_rx_gbeth() The skb is delivered to napi_gro_receive() which may free it, after calling this, dereferencing skb may trigger use-after-free.

In the Linux kernel, the following vulnerability has been resolved: lz4: fix LZ4_decompress_safe_partial read out of bound When partialDecoding, it is EOF if we've either filled the output buffer or can't proceed with reading an offset for following match. In some extreme corner cases when compressed data is suitably corrupted, UAF will occur. As reported by KASAN [1], LZ4_decompress_safe_partial may lead to read out of bound problem during decoding. lz4 upstream has fixed it [2] and this issue has been disscussed here [3] before. current decompression routine was ported from lz4 v1.8.3, bumping lib/lz4 to v1.9.+ is certainly a huge work to be done later, so, we'd better fix it first. [1] https://lore.kernel.org/all/000000000000830d1205cf7f0477@google.com/ [2] https://github.com/lz4/lz4/commit/c5d6f8a8be3927c0bec91bcc58667a6cfad244ad# [3] https://lore.kernel.org/all/CC666AE8-4CA4-4951-B6FB-A2EFDE3AC03B@fb.com/

In the Linux kernel, the following vulnerability has been resolved: moxart: fix potential use-after-free on remove path It was reported that the mmc host structure could be accessed after it was freed in moxart_remove(), so fix this by saving the base register of the device and using it instead of the pointer dereference.

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix use-after-free when reverting termination table When having multiple dests with termination tables and second one or afterwards fails the driver reverts usage of term tables but doesn't reset the assignment in attr->dests[num_vport_dests].termtbl which case a use-after-free when releasing the rule. Fix by resetting the assignment of termtbl to null.

In the Linux kernel, the following vulnerability has been resolved: net: mscc: ocelot: fix use-after-free in ocelot_vlan_del() ocelot_vlan_member_del() will free the struct ocelot_bridge_vlan, so if this is the same as the port's pvid_vlan which we access afterwards, what we're accessing is freed memory. Fix the bug by determining whether to clear ocelot_port->pvid_vlan prior to calling ocelot_vlan_member_del().

In the Linux kernel, the following vulnerability has been resolved: skbuff: fix coalescing for page_pool fragment recycling Fix a use-after-free when using page_pool with page fragments. We encountered this problem during normal RX in the hns3 driver: (1) Initially we have three descriptors in the RX queue. The first one allocates PAGE1 through page_pool, and the other two allocate one half of PAGE2 each. Page references look like this: RX_BD1 _______ PAGE1 RX_BD2 _______ PAGE2 RX_BD3 _________/ (2) Handle RX on the first descriptor. Allocate SKB1, eventually added to the receive queue by tcp_queue_rcv(). (3) Handle RX on the second descriptor. Allocate SKB2 and pass it to netif_receive_skb(): netif_receive_skb(SKB2) ip_rcv(SKB2) SKB3 = skb_clone(SKB2) SKB2 and SKB3 share a reference to PAGE2 through skb_shinfo()->dataref. The other ref to PAGE2 is still held by RX_BD3: SKB2 ---+- PAGE2 SKB3 __/ / RX_BD3 _________/ (3b) Now while handling TCP, coalesce SKB3 with SKB1: tcp_v4_rcv(SKB3) tcp_try_coalesce(to=SKB1, from=SKB3) // succeeds kfree_skb_partial(SKB3) skb_release_data(SKB3) // drops one dataref SKB1 _____ PAGE1 \____ SKB2 _____ PAGE2 / RX_BD3 _________/ In skb_try_coalesce(), __skb_frag_ref() takes a page reference to PAGE2, where it should instead have increased the page_pool frag reference, pp_frag_count. Without coalescing, when releasing both SKB2 and SKB3, a single reference to PAGE2 would be dropped. Now when releasing SKB1 and SKB2, two references to PAGE2 will be dropped, resulting in underflow. (3c) Drop SKB2: af_packet_rcv(SKB2) consume_skb(SKB2) skb_release_data(SKB2) // drops second dataref page_pool_return_skb_page(PAGE2) // drops one pp_frag_count SKB1 _____ PAGE1 \____ PAGE2 / RX_BD3 _________/ (4) Userspace calls recvmsg() Copies SKB1 and releases it. Since SKB3 was coalesced with SKB1, we release the SKB3 page as well: tcp_eat_recv_skb(SKB1) skb_release_data(SKB1) page_pool_return_skb_page(PAGE1) page_pool_return_skb_page(PAGE2) // drops second pp_frag_count (5) PAGE2 is freed, but the third RX descriptor was still using it! In our case this causes IOMMU faults, but it would silently corrupt memory if the IOMMU was disabled. Change the logic that checks whether pp_recycle SKBs can be coalesced. We still reject differing pp_recycle between 'from' and 'to' SKBs, but in order to avoid the situation described above, we also reject coalescing when both 'from' and 'to' are pp_recycled and 'from' is cloned. The new logic allows coalescing a cloned pp_recycle SKB into a page refcounted one, because in this case the release (4) will drop the right reference, the one taken by skb_try_coalesce().

In the Linux kernel, the following vulnerability has been resolved: dm: fix use-after-free in dm_cleanup_zoned_dev() dm_cleanup_zoned_dev() uses queue, so it must be called before blk_cleanup_disk() starts its killing: blk_cleanup_disk->blk_cleanup_queue()->kobject_put()->blk_release_queue()-> ->...RCU...->blk_free_queue_rcu()->kmem_cache_free() Otherwise, RCU callback may be executed first and dm_cleanup_zoned_dev() will touch free'd memory: BUG: KASAN: use-after-free in dm_cleanup_zoned_dev+0x33/0xd0 Read of size 8 at addr ffff88805ac6e430 by task dmsetup/681 CPU: 4 PID: 681 Comm: dmsetup Not tainted 5.17.0-rc2+ #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x57/0x7d print_address_description.constprop.0+0x1f/0x150 ? dm_cleanup_zoned_dev+0x33/0xd0 kasan_report.cold+0x7f/0x11b ? dm_cleanup_zoned_dev+0x33/0xd0 dm_cleanup_zoned_dev+0x33/0xd0 __dm_destroy+0x26a/0x400 ? dm_blk_ioctl+0x230/0x230 ? up_write+0xd8/0x270 dev_remove+0x156/0x1d0 ctl_ioctl+0x269/0x530 ? table_clear+0x140/0x140 ? lock_release+0xb2/0x750 ? remove_all+0x40/0x40 ? rcu_read_lock_sched_held+0x12/0x70 ? lock_downgrade+0x3c0/0x3c0 ? rcu_read_lock_sched_held+0x12/0x70 dm_ctl_ioctl+0xa/0x10 __x64_sys_ioctl+0xb9/0xf0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fb6dfa95c27

In the Linux kernel, the following vulnerability has been resolved: net: arc_emac: Fix use after free in arc_mdio_probe() If bus->state is equal to MDIOBUS_ALLOCATED, mdiobus_free(bus) will free the "bus". But bus->name is still used in the next line, which will lead to a use after free. We can fix it by putting the name in a local variable and make the bus->name point to the rodata section "name",then use the name in the error message without referring to bus to avoid the uaf.

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu: fix use-after-free during gpu recovery [Why] [ 754.862560] refcount_t: underflow; use-after-free. [ 754.862898] Call Trace: [ 754.862903] <TASK> [ 754.862913] amdgpu_job_free_cb+0xc2/0xe1 [amdgpu] [ 754.863543] drm_sched_main.cold+0x34/0x39 [amd_sched] [How] The fw_fence may be not init, check whether dma_fence_init is performed before job free

In the Linux kernel, the following vulnerability has been resolved: peci: cpu: Fix use-after-free in adev_release() When auxiliary_device_add() returns an error, auxiliary_device_uninit() is called, which causes refcount for device to be decremented and .release callback will be triggered. Because adev_release() re-calls auxiliary_device_uninit(), it will cause use-after-free: [ 1269.455172] WARNING: CPU: 0 PID: 14267 at lib/refcount.c:28 refcount_warn_saturate+0x110/0x15 [ 1269.464007] refcount_t: underflow; use-after-free.

In the Linux kernel, the following vulnerability has been resolved: perf: Fix perf_pending_task() UaF Per syzbot it is possible for perf_pending_task() to run after the event is free()'d. There are two related but distinct cases: - the task_work was already queued before destroying the event; - destroying the event itself queues the task_work. The first cannot be solved using task_work_cancel() since perf_release() itself might be called from a task_work (____fput), which means the current->task_works list is already empty and task_work_cancel() won't be able to find the perf_pending_task() entry. The simplest alternative is extending the perf_event lifetime to cover the task_work. The second is just silly, queueing a task_work while you know the event is going away makes no sense and is easily avoided by re-arranging how the event is marked STATE_DEAD and ensuring it goes through STATE_OFF on the way down.