Use After Free

Use After Free vulnerability in Arm Ltd Bifrost GPU Kernel Driver, Arm Ltd Valhall GPU Kernel Driver, Arm Ltd Arm 5th Gen GPU Architecture Kernel Driver allows a local non-privileged user to make improper GPU memory processing operations to gain access to already freed memory.This issue affects Bifrost GPU Kernel Driver: from r43p0 through r49p0; Valhall GPU Kernel Driver: from r43p0 through r49p0; Arm 5th Gen GPU Architecture Kernel Driver: from r43p0 through r49p0.Show less

In the Linux kernel, the following vulnerability has been resolved: kcm: Serialise kcm_sendmsg() for the same socket. syzkaller reported UAF in kcm_release(). [0] The scenario is 1. Thread A builds a skb with MSG_MORE and sets kcm->seq_skb. 2. Thread A resumes building skb from kcm->seq_skb but is blocked by sk_stream_wait_memory() 3. Thread B calls sendmsg() concurrently, finishes building kcm->seq_skb and puts the skb to the write queue 4. Thread A faces an error and finally frees skb that is already in the write queue 5. kcm_release() does double-free the skb in the write queue When a thread is building a MSG_MORE skb, another thread must not touch it. Let's add a per-sk mutex and serialise kcm_sendmsg(). [0]: BUG: KASAN: slab-use-after-free in __skb_unlink include/linux/skbuff.h:2366 [inline] BUG: KASAN: slab-use-after-free in __skb_dequeue include/linux/skbuff.h:2385 [inline] BUG: KASAN: slab-use-after-free in __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline] BUG: KASAN: slab-use-after-free in __skb_queue_purge include/linux/skbuff.h:3181 [inline] BUG: KASAN: slab-use-after-free in kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691 Read of size 8 at addr ffff0000ced0fc80 by task syz-executor329/6167 CPU: 1 PID: 6167 Comm: syz-executor329 Tainted: G B 6.8.0-rc5-syzkaller-g9abbc24128bc #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call trace: dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:291 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:298 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0x178/0x518 mm/kasan/report.c:488 kasan_report+0xd8/0x138 mm/kasan/report.c:601 __asan_report_load8_noabort+0x20/0x2c mm/kasan/report_generic.c:381 __skb_unlink include/linux/skbuff.h:2366 [inline] __skb_dequeue include/linux/skbuff.h:2385 [inline] __skb_queue_purge_reason include/linux/skbuff.h:3175 [inline] __skb_queue_purge include/linux/skbuff.h:3181 [inline] kcm_release+0x170/0x4c8 net/kcm/kcmsock.c:1691 __sock_release net/socket.c:659 [inline] sock_close+0xa4/0x1e8 net/socket.c:1421 __fput+0x30c/0x738 fs/file_table.c:376 ____fput+0x20/0x30 fs/file_table.c:404 task_work_run+0x230/0x2e0 kernel/task_work.c:180 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x618/0x1f64 kernel/exit.c:871 do_group_exit+0x194/0x22c kernel/exit.c:1020 get_signal+0x1500/0x15ec kernel/signal.c:2893 do_signal+0x23c/0x3b44 arch/arm64/kernel/signal.c:1249 do_notify_resume+0x74/0x1f4 arch/arm64/kernel/entry-common.c:148 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline] el0_svc+0xac/0x168 arch/arm64/kernel/entry-common.c:713 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 Allocated by task 6166: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:68 kasan_save_alloc_info+0x70/0x84 mm/kasan/generic.c:626 unpoison_slab_object mm/kasan/common.c:314 [inline] __kasan_slab_alloc+0x74/0x8c mm/kasan/common.c:340 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3813 [inline] slab_alloc_node mm/slub.c:3860 [inline] kmem_cache_alloc_node+0x204/0x4c0 mm/slub.c:3903 __alloc_skb+0x19c/0x3d8 net/core/skbuff.c:641 alloc_skb include/linux/skbuff.h:1296 [inline] kcm_sendmsg+0x1d3c/0x2124 net/kcm/kcmsock.c:783 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_sendmsg+0x220/0x2c0 net/socket.c:768 splice_to_socket+0x7cc/0xd58 fs/splice.c:889 do_splice_from fs/splice.c:941 [inline] direct_splice_actor+0xec/0x1d8 fs/splice.c:1164 splice_direct_to_actor+0x438/0xa0c fs/splice.c:1108 do_splice_direct_actor ---truncated---Show less

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.Show less

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:2437Show less

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).Show less

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.Show less

In the Linux kernel, the following vulnerability has been resolved: tracing: Have format file honor EVENT_FILE_FL_FREED When eventfs was introduced, special care had to be done to coordinate the freeing of the file meta data with the files that are exposed to user space. The file meta data would have a ref count that is set when the file is created and would be decremented and freed after the last user that opened the file closed it. When the file meta data was to be freed, it would set a flag (EVENT_FILE_FL_FREED) to denote that the file is freed, and any new references made (like new opens or reads) would fail as it is marked freed. This allowed other meta data to be freed after this flag was set (under the event_mutex). All the files that were dynamically created in the events directory had a pointer to the file meta data and would call event_release() when the last reference to the user space file was closed. This would be the time that it is safe to free the file meta data. A shortcut was made for the "format" file. It's i_private would point to the "call" entry directly and not point to the file's meta data. This is because all format files are the same for the same "call", so it was thought there was no reason to differentiate them. The other files maintain state (like the "enable", "trigger", etc). But this meant if the file were to disappear, the "format" file would be unaware of it. This caused a race that could be trigger via the user_events test (that would create dynamic events and free them), and running a loop that would read the user_events format files: In one console run: # cd tools/testing/selftests/user_events # while true; do ./ftrace_test; done And in another console run: # cd /sys/kernel/tracing/ # while true; do cat events/user_events/__test_event/format; done 2>/dev/null With KASAN memory checking, it would trigger a use-after-free bug report (which was a real bug). This was because the format file was not checking the file's meta data flag "EVENT_FILE_FL_FREED", so it would access the event that the file meta data pointed to after the event was freed. After inspection, there are other locations that were found to not check the EVENT_FILE_FL_FREED flag when accessing the trace_event_file. Add a new helper function: event_file_file() that will make sure that the event_mutex is held, and will return NULL if the trace_event_file has the EVENT_FILE_FL_FREED flag set. Have the first reference of the struct file pointer use event_file_file() and check for NULL. Later uses can still use the event_file_data() helper function if the event_mutex is still held and was not released since the event_file_file() call.Show less

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]Show less

In the Linux kernel, the following vulnerability has been resolved: usb: vhci-hcd: Do not drop references before new references are gained At a few places the driver carries stale pointers to references that can still be used. Make sure that does not happen. This strictly speaking closes ZDI-CAN-22273, though there may be similar races in the driver.Show less

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: unregister flowtable hooks on netns exit Unregister flowtable hooks before they are releases via nf_tables_flowtable_destroy() otherwise hook core reports UAF. BUG: KASAN: use-after-free in nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142 Read of size 4 at addr ffff8880736f7438 by task syz-executor579/3666 CPU: 0 PID: 3666 Comm: syz-executor579 Not tainted 5.16.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] __dump_stack lib/dump_stack.c:88 [inline] lib/dump_stack.c:106 dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106 lib/dump_stack.c:106 print_address_description+0x65/0x380 mm/kasan/report.c:247 mm/kasan/report.c:247 __kasan_report mm/kasan/report.c:433 [inline] __kasan_report mm/kasan/report.c:433 [inline] mm/kasan/report.c:450 kasan_report+0x19a/0x1f0 mm/kasan/report.c:450 mm/kasan/report.c:450 nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142 __nf_register_net_hook+0x27e/0x8d0 net/netfilter/core.c:429 net/netfilter/core.c:429 nf_register_net_hook+0xaa/0x180 net/netfilter/core.c:571 net/netfilter/core.c:571 nft_register_flowtable_net_hooks+0x3c5/0x730 net/netfilter/nf_tables_api.c:7232 net/netfilter/nf_tables_api.c:7232 nf_tables_newflowtable+0x2022/0x2cf0 net/netfilter/nf_tables_api.c:7430 net/netfilter/nf_tables_api.c:7430 nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline] net/netfilter/nfnetlink.c:652 nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] net/netfilter/nfnetlink.c:652 nfnetlink_rcv+0x10e6/0x2550 net/netfilter/nfnetlink.c:652 net/netfilter/nfnetlink.c:652 __nft_release_hook() calls nft_unregister_flowtable_net_hooks() which only unregisters the hooks, then after RCU grace period, it is guaranteed that no packets add new entries to the flowtable (no flow offload rules and flowtable hooks are reachable from packet path), so it is safe to call nf_flow_table_free() which cleans up the remaining entries from the flowtable (both software and hardware) and it unbinds the flow_block.Show less

In the Linux kernel, the following vulnerability has been resolved: RDMA/cma: Do not change route.addr.src_addr outside state checks If the state is not idle then resolve_prepare_src() should immediately fail and no change to global state should happen. However, it unconditionally overwrites the src_addr trying to build a temporary any address. For instance if the state is already RDMA_CM_LISTEN then this will corrupt the src_addr and would cause the test in cma_cancel_operation(): if (cma_any_addr(cma_src_addr(id_priv)) && !id_priv->cma_dev) Which would manifest as this trace from syzkaller: BUG: KASAN: use-after-free in __list_add_valid+0x93/0xa0 lib/list_debug.c:26 Read of size 8 at addr ffff8881546491e0 by task syz-executor.1/32204 CPU: 1 PID: 32204 Comm: syz-executor.1 Not tainted 5.12.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232 __kasan_report mm/kasan/report.c:399 [inline] kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416 __list_add_valid+0x93/0xa0 lib/list_debug.c:26 __list_add include/linux/list.h:67 [inline] list_add_tail include/linux/list.h:100 [inline] cma_listen_on_all drivers/infiniband/core/cma.c:2557 [inline] rdma_listen+0x787/0xe00 drivers/infiniband/core/cma.c:3751 ucma_listen+0x16a/0x210 drivers/infiniband/core/ucma.c:1102 ucma_write+0x259/0x350 drivers/infiniband/core/ucma.c:1732 vfs_write+0x28e/0xa30 fs/read_write.c:603 ksys_write+0x1ee/0x250 fs/read_write.c:658 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae This is indicating that an rdma_id_private was destroyed without doing cma_cancel_listens(). Instead of trying to re-use the src_addr memory to indirectly create an any address derived from the dst build one explicitly on the stack and bind to that as any other normal flow would do. rdma_bind_addr() will copy it over the src_addr once it knows the state is valid. This is similar to commit bc0bdc5afaa7 ("RDMA/cma: Do not change route.addr.src_addr.ss_family")Show less

In the Linux kernel, the following vulnerability has been resolved: blktrace: fix use after free for struct blk_trace When tracing the whole disk, 'dropped' and 'msg' will be created under 'q->debugfs_dir' and 'bt->dir' is NULL, thus blk_trace_free() won't remove those files. What's worse, the following UAF can be triggered because of accessing stale 'dropped' and 'msg': ================================================================== BUG: KASAN: use-after-free in blk_dropped_read+0x89/0x100 Read of size 4 at addr ffff88816912f3d8 by task blktrace/1188 CPU: 27 PID: 1188 Comm: blktrace Not tainted 5.17.0-rc4-next-20220217+ #469 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-4 Call Trace: <TASK> dump_stack_lvl+0x34/0x44 print_address_description.constprop.0.cold+0xab/0x381 ? blk_dropped_read+0x89/0x100 ? blk_dropped_read+0x89/0x100 kasan_report.cold+0x83/0xdf ? blk_dropped_read+0x89/0x100 kasan_check_range+0x140/0x1b0 blk_dropped_read+0x89/0x100 ? blk_create_buf_file_callback+0x20/0x20 ? kmem_cache_free+0xa1/0x500 ? do_sys_openat2+0x258/0x460 full_proxy_read+0x8f/0xc0 vfs_read+0xc6/0x260 ksys_read+0xb9/0x150 ? vfs_write+0x3d0/0x3d0 ? fpregs_assert_state_consistent+0x55/0x60 ? exit_to_user_mode_prepare+0x39/0x1e0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fbc080d92fd Code: ce 20 00 00 75 10 b8 00 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 1 RSP: 002b:00007fbb95ff9cb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007fbb95ff9dc0 RCX: 00007fbc080d92fd RDX: 0000000000000100 RSI: 00007fbb95ff9cc0 RDI: 0000000000000045 RBP: 0000000000000045 R08: 0000000000406299 R09: 00000000fffffffd R10: 000000000153afa0 R11: 0000000000000293 R12: 00007fbb780008c0 R13: 00007fbb78000938 R14: 0000000000608b30 R15: 00007fbb780029c8 </TASK> Allocated by task 1050: kasan_save_stack+0x1e/0x40 __kasan_kmalloc+0x81/0xa0 do_blk_trace_setup+0xcb/0x410 __blk_trace_setup+0xac/0x130 blk_trace_ioctl+0xe9/0x1c0 blkdev_ioctl+0xf1/0x390 __x64_sys_ioctl+0xa5/0xe0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 1050: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_set_free_info+0x20/0x30 __kasan_slab_free+0x103/0x180 kfree+0x9a/0x4c0 __blk_trace_remove+0x53/0x70 blk_trace_ioctl+0x199/0x1c0 blkdev_common_ioctl+0x5e9/0xb30 blkdev_ioctl+0x1a5/0x390 __x64_sys_ioctl+0xa5/0xe0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff88816912f380 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 88 bytes inside of 96-byte region [ffff88816912f380, ffff88816912f3e0) The buggy address belongs to the page: page:000000009a1b4e7c refcount:1 mapcount:0 mapping:0000000000000000 index:0x0f flags: 0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff) raw: 0017ffffc0000200 ffffea00044f1100 dead000000000002 ffff88810004c780 raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88816912f280: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88816912f300: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff88816912f380: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88816912f400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88816912f480: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================Show less

In the Linux kernel, the following vulnerability has been resolved: netfilter: fix use-after-free in __nf_register_net_hook() We must not dereference @new_hooks after nf_hook_mutex has been released, because other threads might have freed our allocated hooks already. BUG: KASAN: use-after-free in nf_hook_entries_get_hook_ops include/linux/netfilter.h:130 [inline] BUG: KASAN: use-after-free in hooks_validate net/netfilter/core.c:171 [inline] BUG: KASAN: use-after-free in __nf_register_net_hook+0x77a/0x820 net/netfilter/core.c:438 Read of size 2 at addr ffff88801c1a8000 by task syz-executor237/4430 CPU: 1 PID: 4430 Comm: syz-executor237 Not tainted 5.17.0-rc5-syzkaller-00306-g2293be58d6a1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> __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/0x336 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 nf_hook_entries_get_hook_ops include/linux/netfilter.h:130 [inline] hooks_validate net/netfilter/core.c:171 [inline] __nf_register_net_hook+0x77a/0x820 net/netfilter/core.c:438 nf_register_net_hook+0x114/0x170 net/netfilter/core.c:571 nf_register_net_hooks+0x59/0xc0 net/netfilter/core.c:587 nf_synproxy_ipv6_init+0x85/0xe0 net/netfilter/nf_synproxy_core.c:1218 synproxy_tg6_check+0x30d/0x560 net/ipv6/netfilter/ip6t_SYNPROXY.c:81 xt_check_target+0x26c/0x9e0 net/netfilter/x_tables.c:1038 check_target net/ipv6/netfilter/ip6_tables.c:530 [inline] find_check_entry.constprop.0+0x7f1/0x9e0 net/ipv6/netfilter/ip6_tables.c:573 translate_table+0xc8b/0x1750 net/ipv6/netfilter/ip6_tables.c:735 do_replace net/ipv6/netfilter/ip6_tables.c:1153 [inline] do_ip6t_set_ctl+0x56e/0xb90 net/ipv6/netfilter/ip6_tables.c:1639 nf_setsockopt+0x83/0xe0 net/netfilter/nf_sockopt.c:101 ipv6_setsockopt+0x122/0x180 net/ipv6/ipv6_sockglue.c:1024 rawv6_setsockopt+0xd3/0x6a0 net/ipv6/raw.c:1084 __sys_setsockopt+0x2db/0x610 net/socket.c:2180 __do_sys_setsockopt net/socket.c:2191 [inline] __se_sys_setsockopt net/socket.c:2188 [inline] __x64_sys_setsockopt+0xba/0x150 net/socket.c:2188 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 RIP: 0033:0x7f65a1ace7d9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 71 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f65a1a7f308 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f65a1ace7d9 RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 00007f65a1b574c8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000020000000 R11: 0000000000000246 R12: 00007f65a1b55130 R13: 00007f65a1b574c0 R14: 00007f65a1b24090 R15: 0000000000022000 </TASK> The buggy address belongs to the page: page:ffffea0000706a00 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1c1a8 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000000 ffffea0001c1b108 ffffea000046dd08 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52dc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_ZERO), pid 4430, ts 1061781545818, free_ts 1061791488993 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389 __alloc_pages_node include/linux/gfp.h:572 [inline] alloc_pages_node include/linux/gfp.h:595 [inline] kmalloc_large_node+0x62/0x130 mm/slub.c:4438 __kmalloc_node+0x35a/0x4a0 mm/slub. ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_queue: fix possible use-after-free Eric Dumazet says: The sock_hold() side seems suspect, because there is no guarantee that sk_refcnt is not already 0. On failure, we cannot queue the packet and need to indicate an error. The packet will be dropped by the caller. v2: split skb prefetch hunk into separate changeShow less