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KASAN: use-after-free Write in skb_release_data

Status: premoderation: reported on 2025/04/23 21:40
Reported-by: syzbot+fda596cfcc42477073f3@syzkaller.appspotmail.com
First crash: 24d, last: 24d
▶ ▼ Similar bugs (10)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Write in skb_release_data net C 1903 2549d 2602d 8/28 fixed on 2018/08/07 13:43
android-414 KASAN: use-after-free Write in skb_release_data 3 2041d 2120d 0/1 auto-closed as invalid on 2020/02/13 13:09
linux-4.19 KASAN: use-after-free Write in skb_release_data 1 1862d 1862d 0/1 auto-closed as invalid on 2020/08/10 01:37
upstream KASAN: use-after-free Write in skb_release_data (2) net C done unreliable 875 1347d 2407d 0/28 auto-obsoleted due to no activity on 2023/04/16 03:59
linux-4.19 KASAN: use-after-free Write in skb_release_data (2) 3 1477d 1553d 0/1 auto-closed as invalid on 2021/08/30 12:28
android-54 KASAN: use-after-free Write in skb_release_data 2 1753d 1784d 0/2 auto-closed as invalid on 2020/11/26 21:03
upstream KMSAN: uninit-value in skb_release_data (3) net C 10 1033d 1712d 0/28 auto-obsoleted due to no activity on 2022/11/17 07:20
linux-6.1 KASAN: use-after-free Read in skb_release_data origin:lts-only syz inconclusive 26 304d 395d 0/3 upstream: reported syz repro on 2024/04/17 18:13
linux-5.15 KASAN: use-after-free Read in skb_release_data 1 771d 771d 0/3 auto-obsoleted due to no activity on 2023/08/06 13:46
upstream general protection fault in skb_release_data (2) net bluetooth C done error 703 47d 1712d 0/28 upstream: reported C repro on 2020/09/09 09:58

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
BUG: KASAN: use-after-free in atomic_sub_return include/asm-generic/atomic-instrumented.h:160 [inline]
BUG: KASAN: use-after-free in skb_release_data+0x102/0x6f0 net/core/skbuff.c:615
Write of size 4 at addr ffff8881249c44a0 by task kworker/u5:3/32027

CPU: 1 PID: 32027 Comm: kworker/u5:3 Tainted: G        W         5.10.236-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: hci0 hci_power_on
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
 print_address_description+0x81/0x3b0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0x179/0x1c0 mm/kasan/report.c:452
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x293/0x2a0 mm/kasan/generic.c:189
 __kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic_sub_return include/asm-generic/atomic-instrumented.h:160 [inline]
 skb_release_data+0x102/0x6f0 net/core/skbuff.c:615
 skb_release_all net/core/skbuff.c:680 [inline]
 __kfree_skb net/core/skbuff.c:694 [inline]
 kfree_skb+0xb9/0x320 net/core/skbuff.c:713
 hci_dev_do_open+0xe4a/0x11c0 net/bluetooth/hci_core.c:1627
 hci_power_on+0x1c1/0x5e0 net/bluetooth/hci_core.c:2253
 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301
 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447
 kthread+0x34b/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Allocated by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8881249c4400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 160 bytes inside of
 512-byte region [ffff8881249c4400, ffff8881249c4600)
The buggy address belongs to the page:
page:ffffea0004927100 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1249c4
head:ffffea0004927100 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 0000000000000000 0000000100000001 ffff888100043080
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 22200, ts 2846919093331, free_ts 2846820958983
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x166/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5349
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1808 [inline]
 new_slab+0x80/0x400 mm/slub.c:1869
 new_slab_objects mm/slub.c:2627 [inline]
 ___slab_alloc+0x302/0x4b0 mm/slub.c:2791
 __slab_alloc+0x63/0xa0 mm/slub.c:2831
 slab_alloc_node mm/slub.c:2913 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 __kmalloc_track_caller+0x1f8/0x320 mm/slub.c:4536
 __kmalloc_reserve net/core/skbuff.c:144 [inline]
 __alloc_skb+0xbc/0x510 net/core/skbuff.c:212
 alloc_skb include/linux/skbuff.h:1126 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 fdb_notify+0x77/0x120 net/bridge/br_fdb.c:739
 br_fdb_update+0x505/0x660 net/bridge/br_fdb.c:618
 br_handle_frame_finish+0x1d9/0x1180 net/bridge/br_input.c:102
 nf_hook_bridge_pre net/bridge/br_input.c:259 [inline]
 br_handle_frame+0x3f0/0x8d0 net/bridge/br_input.c:363
 __netif_receive_skb_core+0x11a9/0x3760 net/core/dev.c:5295
 __netif_receive_skb_one_core net/core/dev.c:5399 [inline]
 __netif_receive_skb+0x11c/0x530 net/core/dev.c:5515
 process_backlog+0x31c/0x650 net/core/dev.c:6422
 napi_poll net/core/dev.c:6873 [inline]
 net_rx_action+0x516/0x10d0 net/core/dev.c:6943
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2ae/0x2d0 mm/page_alloc.c:3336
 free_unref_page mm/page_alloc.c:3391 [inline]
 free_the_page+0x9e/0x370 mm/page_alloc.c:5408
 __free_pages+0x67/0xc0 mm/page_alloc.c:5419
 __vunmap+0x7c1/0x940 mm/vmalloc.c:2301
 __vfree mm/vmalloc.c:2350 [inline]
 vfree+0x5c/0x80 mm/vmalloc.c:2381
 kcov_mmap+0x93/0x130 kernel/kcov.c:489
 call_mmap include/linux/fs.h:2063 [inline]
 mmap_file+0x5f/0xb0 mm/util.c:1085
 __mmap_region mm/mmap.c:1872 [inline]
 mmap_region+0x149f/0x1cd0 mm/mmap.c:3063
 do_mmap+0x800/0xeb0 mm/mmap.c:1649
 vm_mmap_pgoff+0x201/0x390 mm/util.c:543
 ksys_mmap_pgoff+0x16f/0x1f0 mm/mmap.c:1700
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:95 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline]
 __x64_sys_mmap+0x103/0x120 arch/x86/kernel/sys_x86_64.c:86
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Memory state around the buggy address:
 ffff8881249c4380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881249c4400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881249c4480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff8881249c4500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881249c4580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
==================================================================
BUG: KASAN: double-free or invalid-free in slab_free mm/slub.c:3203 [inline]
BUG: KASAN: double-free or invalid-free in kmem_cache_free+0xa9/0x1e0 mm/slub.c:3219

CPU: 0 PID: 32027 Comm: kworker/u5:3 Tainted: G    B   W         5.10.236-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: hci0 hci_power_on
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack_lvl+0x1e2/0x24b lib/dump_stack.c:118
 print_address_description+0x81/0x3b0 mm/kasan/report.c:248
 kasan_report_invalid_free+0x52/0x80 mm/kasan/report.c:374
 ____kasan_slab_free+0x139/0x160 mm/kasan/common.c:-1
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
 kasan_slab_free include/linux/kasan.h:220 [inline]
 slab_free_hook mm/slub.c:1595 [inline]
 slab_free_freelist_hook+0xc0/0x190 mm/slub.c:1621
 slab_free mm/slub.c:3203 [inline]
 kmem_cache_free+0xa9/0x1e0 mm/slub.c:3219
 kfree_skbmem+0x104/0x170 net/core/skbuff.c:-1
 __kfree_skb net/core/skbuff.c:695 [inline]
 kfree_skb+0xc1/0x320 net/core/skbuff.c:713
 hci_dev_do_open+0xe4a/0x11c0 net/bluetooth/hci_core.c:1627
 hci_power_on+0x1c1/0x5e0 net/bluetooth/hci_core.c:2253
 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301
 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447
 kthread+0x34b/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Allocated by task 31681:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:430 [inline]
 __kasan_slab_alloc+0xb1/0xe0 mm/kasan/common.c:463
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x61/0x2f0 mm/slab.h:583
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x168/0x2e0 mm/slub.c:2960
 skb_clone+0x1de/0x370 net/core/skbuff.c:1467
 hci_cmd_work+0xb3/0x270 net/bluetooth/hci_core.c:4995
 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301
 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447
 kthread+0x34b/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

Freed by task 31681:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x121/0x160 mm/kasan/common.c:362
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
 kasan_slab_free include/linux/kasan.h:220 [inline]
 slab_free_hook mm/slub.c:1595 [inline]
 slab_free_freelist_hook+0xc0/0x190 mm/slub.c:1621
 slab_free mm/slub.c:3203 [inline]
 kmem_cache_free+0xa9/0x1e0 mm/slub.c:3219
 kfree_skbmem+0x104/0x170 net/core/skbuff.c:-1
 __kfree_skb net/core/skbuff.c:695 [inline]
 kfree_skb+0xc1/0x320 net/core/skbuff.c:713
 hci_cmd_work+0xa5/0x270 net/bluetooth/hci_core.c:4993
 process_one_work+0x6dc/0xbd0 kernel/workqueue.c:2301
 worker_thread+0xaea/0x1510 kernel/workqueue.c:2447
 kthread+0x34b/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

The buggy address belongs to the object at ffff888111d62500
 which belongs to the cache skbuff_head_cache of size 248
The buggy address is located 0 bytes inside of
 248-byte region [ffff888111d62500, ffff888111d625f8)
The buggy address belongs to the page:
page:ffffea0004475880 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111d62
flags: 0x4000000000000200(slab)
raw: 4000000000000200 dead000000000100 dead000000000122 ffff888107d95200
raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 31248, ts 2864780120825, free_ts 2864778258914
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x166/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x2d8c/0x2f30 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x435/0xaf0 mm/page_alloc.c:5349
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1808 [inline]
 new_slab+0x80/0x400 mm/slub.c:1869
 new_slab_objects mm/slub.c:2627 [inline]
 ___slab_alloc+0x302/0x4b0 mm/slub.c:2791
 __slab_alloc+0x63/0xa0 mm/slub.c:2831
 slab_alloc_node mm/slub.c:2913 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x1b9/0x2e0 mm/slub.c:2960
 skb_clone+0x1de/0x370 net/core/skbuff.c:1467
 deliver_clone net/bridge/br_forward.c:119 [inline]
 maybe_deliver+0x1a4/0x2a0 net/bridge/br_forward.c:181
 br_flood+0x2e2/0x420 net/bridge/br_forward.c:223
 br_handle_frame_finish+0xe4d/0x1180 net/bridge/br_input.c:173
 nf_hook_bridge_pre net/bridge/br_input.c:259 [inline]
 br_handle_frame+0x3f0/0x8d0 net/bridge/br_input.c:363
 __netif_receive_skb_core+0x11a9/0x3760 net/core/dev.c:5295
 __netif_receive_skb_one_core net/core/dev.c:5399 [inline]
 __netif_receive_skb+0x11c/0x530 net/core/dev.c:5515
 process_backlog+0x31c/0x650 net/core/dev.c:6422
 napi_poll net/core/dev.c:6873 [inline]
 net_rx_action+0x516/0x10d0 net/core/dev.c:6943
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2ae/0x2d0 mm/page_alloc.c:3336
 free_unref_page mm/page_alloc.c:3391 [inline]
 free_the_page+0x9e/0x370 mm/page_alloc.c:5408
 __free_pages+0x67/0xc0 mm/page_alloc.c:5419
 __free_slab+0xcf/0x190 mm/slub.c:1894
 free_slab mm/slub.c:1909 [inline]
 discard_slab mm/slub.c:1915 [inline]
 unfreeze_partials+0x15e/0x190 mm/slub.c:2410
 put_cpu_partial+0xbf/0x180 mm/slub.c:2446
 __slab_free+0x2c8/0x3a0 mm/slub.c:3095
 do_slab_free mm/slub.c:3191 [inline]
 ___cache_free+0x111/0x130 mm/slub.c:3210
 qlink_free+0x50/0x90 mm/kasan/quarantine.c:157
 qlist_free_all+0x47/0xb0 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x15a/0x170 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:440
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x61/0x2f0 mm/slab.h:583
 slab_alloc_node mm/slub.c:2947 [inline]
 slab_alloc mm/slub.c:2955 [inline]
 kmem_cache_alloc+0x168/0x2e0 mm/slub.c:2960
 kmem_cache_alloc_node include/linux/slab.h:423 [inline]
 alloc_task_struct_node kernel/fork.c:177 [inline]
 dup_task_struct+0x57/0xc30 kernel/fork.c:912
 copy_process+0x5c8/0x3340 kernel/fork.c:2016

Memory state around the buggy address:
 ffff888111d62400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888111d62480: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc
>ffff888111d62500: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888111d62580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
 ffff888111d62600: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/23 21:39 android13-5.10-lts ba8b8b193394 73a168d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: use-after-free Write in skb_release_data
* Struck through repros no longer work on HEAD.