syzbot


KASAN: use-after-free Read in sk_psock_verdict_data_ready (2)

Status: premoderation: reported on 2025/10/05 06:35
Reported-by: syzbot+baaa86dadbb5184904b4@syzkaller.appspotmail.com
First crash: 7d05h, last: 7d05h
Similar bugs (10)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 KASAN: use-after-free Read in sk_psock_verdict_data_ready 19 21 187d 404d 0/2 auto-obsoleted due to no activity on 2025/07/06 21:52
linux-5.15 KASAN: use-after-free Read in sk_psock_verdict_data_ready 19 1 420d 420d 0/3 auto-obsoleted due to no activity on 2024/11/26 04:55
android-6-1 KASAN: use-after-free Read in sk_psock_verdict_data_ready 19 2 336d 369d 0/2 auto-obsoleted due to no activity on 2025/02/08 01:10
upstream general protection fault in sk_psock_verdict_data_ready net 2 2 859d 864d 0/29 auto-obsoleted due to no activity on 2023/09/14 09:29
upstream KASAN: slab-use-after-free Read in sk_psock_verdict_data_ready (2) bpf net 19 2 307d 332d 0/29 auto-obsoleted due to no activity on 2025/04/03 12:37
upstream BUG: unable to handle kernel NULL pointer dereference in sk_psock_verdict_data_ready bpf net 10 C unreliable 15 588d 708d 25/29 fixed on 2024/04/02 10:57
upstream KASAN: slab-use-after-free Read in sk_psock_verdict_data_ready bpf net 19 1 497d 493d 0/29 auto-obsoleted due to no activity on 2024/08/31 11:03
upstream KASAN: slab-use-after-free Read in sk_psock_verdict_data_ready (3) bpf net 19 5 55d 173d 0/29 upstream: reported on 2025/04/22 10:12
android-6-1 BUG: unable to handle kernel NULL pointer dereference in sk_psock_verdict_data_ready origin:upstream missing-backport 10 C 204 469d 607d 0/2 auto-obsoleted due to no activity on 2024/09/07 14:49
linux-6.1 BUG: unable to handle kernel NULL pointer dereference in sk_psock_verdict_data_ready origin:upstream 10 C done 1 605d 605d 3/3 fixed on 2024/03/18 12:46

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in sk_psock_verdict_data_ready+0x62/0x1d0 net/core/skmsg.c:1243
Read of size 8 at addr ffff888117af34a0 by task syz.7.3181/12239

CPU: 0 PID: 12239 Comm: syz.7.3181 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106
 print_address_description+0x71/0x200 mm/kasan/report.c:316
 print_report+0x4a/0x60 mm/kasan/report.c:420
 kasan_report+0x122/0x150 mm/kasan/report.c:524
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:351
 sk_psock_verdict_data_ready+0x62/0x1d0 net/core/skmsg.c:1243
 unix_stream_sendmsg+0x625/0xa70 net/unix/af_unix.c:2248
 sock_sendmsg_nosec net/socket.c:716 [inline]
 __sock_sendmsg net/socket.c:728 [inline]
 ____sys_sendmsg+0x5a9/0x990 net/socket.c:2509
 ___sys_sendmsg+0x21c/0x290 net/socket.c:2563
 __sys_sendmsg net/socket.c:2592 [inline]
 __do_sys_sendmsg net/socket.c:2601 [inline]
 __se_sys_sendmsg net/socket.c:2599 [inline]
 __x64_sys_sendmsg+0x1f0/0x2c0 net/socket.c:2599
 x64_sys_call+0x171/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f7a4718eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7a47f5a038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f7a473e5fa0 RCX: 00007f7a4718eec9
RDX: 0000000000000003 RSI: 0000200000000980 RDI: 0000000000000004
RBP: 00007f7a47211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7a473e6038 R14: 00007f7a473e5fa0 R15: 00007ffc844e72e8
 </TASK>

Allocated by task 12239:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505
 __kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:333
 kasan_slab_alloc include/linux/kasan.h:202 [inline]
 slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768
 slab_alloc_node mm/slub.c:3382 [inline]
 slab_alloc mm/slub.c:3392 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3399 [inline]
 kmem_cache_alloc_lru+0x104/0x280 mm/slub.c:3415
 alloc_inode_sb include/linux/fs.h:3263 [inline]
 sock_alloc_inode+0x28/0xc0 net/socket.c:304
 alloc_inode fs/inode.c:264 [inline]
 new_inode_pseudo+0x70/0x1f0 fs/inode.c:1073
 sock_alloc net/socket.c:629 [inline]
 __sock_create+0x12c/0x7c0 net/socket.c:1504
 sock_create net/socket.c:1596 [inline]
 __sys_socketpair+0x218/0x5b0 net/socket.c:1727
 __do_sys_socketpair net/socket.c:1776 [inline]
 __se_sys_socketpair net/socket.c:1773 [inline]
 __x64_sys_socketpair+0x9b/0xb0 net/socket.c:1773
 x64_sys_call+0x6e/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:54
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 13:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516
 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:241
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249
 kasan_slab_free include/linux/kasan.h:178 [inline]
 slab_free_hook mm/slub.c:1750 [inline]
 slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776
 slab_free mm/slub.c:3712 [inline]
 kmem_cache_free+0x12d/0x300 mm/slub.c:3737
 sock_free_inode+0x20/0x30 net/socket.c:325
 i_callback+0x5a/0x80 fs/inode.c:253
 rcu_do_batch+0x515/0xb90 kernel/rcu/tree.c:2297
 rcu_core+0x5a5/0xe70 kernel/rcu/tree.c:2557
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2574
 handle_softirqs+0x1d7/0x600 kernel/softirq.c:642
 run_ksoftirqd+0x28/0x30 kernel/softirq.c:1019
 smpboot_thread_fn+0x4a0/0x910 kernel/smpboot.c:164
 kthread+0x281/0x320 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496
 __call_rcu_common kernel/rcu/tree.c:2807 [inline]
 call_rcu+0xd4/0xf90 kernel/rcu/tree.c:2926
 destroy_inode fs/inode.c:319 [inline]
 evict+0x7f6/0x890 fs/inode.c:723
 iput_final fs/inode.c:1844 [inline]
 iput+0x620/0x670 fs/inode.c:1870
 dentry_unlink_inode+0x33d/0x3f0 fs/dcache.c:405
 __dentry_kill+0x460/0x670 fs/dcache.c:611
 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
 dput+0x42/0x80 fs/dcache.c:918
 __fput+0x5be/0x8f0 fs/file_table.c:328
 ____fput+0x15/0x20 fs/file_table.c:348
 task_work_run+0x1db/0x240 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0x5a/0xa0 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Second to last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496
 __call_rcu_common kernel/rcu/tree.c:2807 [inline]
 call_rcu+0xd4/0xf90 kernel/rcu/tree.c:2926
 destroy_inode fs/inode.c:319 [inline]
 evict+0x7f6/0x890 fs/inode.c:723
 iput_final fs/inode.c:1844 [inline]
 iput+0x620/0x670 fs/inode.c:1870
 __sock_release net/socket.c:664 [inline]
 sock_release+0x122/0x150 net/socket.c:680
 netlink_kernel_release+0x4d/0x60 net/netlink/af_netlink.c:2069
 diag_net_exit+0x40/0x60 net/core/sock_diag.c:325
 ops_exit_list net/core/net_namespace.c:172 [inline]
 cleanup_net+0x5ad/0xb00 net/core/net_namespace.c:604
 process_one_work+0x71f/0xc40 kernel/workqueue.c:2302
 worker_thread+0xa29/0x11f0 kernel/workqueue.c:2449
 kthread+0x281/0x320 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

The buggy address belongs to the object at ffff888117af3480
 which belongs to the cache sock_inode_cache of size 832
The buggy address is located 32 bytes inside of
 832-byte region [ffff888117af3480, ffff888117af37c0)

The buggy address belongs to the physical page:
page:ffffea00045ebc00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x117af0
head:ffffea00045ebc00 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 0000000000000000 dead000000000001 ffff888108c5a180
raw: 0000000000000000 0000000000110011 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Reclaimable, gfp_mask 0x1d20d0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 10693, tgid 10693 (syz-executor), ts 384840495172, free_ts 358382838755
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2650
 get_page_from_freelist+0x2c7b/0x2cf0 mm/page_alloc.c:4554
 __alloc_pages+0x1c3/0x450 mm/page_alloc.c:5868
 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
 allocate_slab mm/slub.c:1967 [inline]
 new_slab+0x98/0x3d0 mm/slub.c:2020
 ___slab_alloc+0x6bd/0xb20 mm/slub.c:3177
 __slab_alloc+0x5e/0xa0 mm/slub.c:3263
 slab_alloc_node mm/slub.c:3348 [inline]
 slab_alloc mm/slub.c:3392 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3399 [inline]
 kmem_cache_alloc_lru+0x144/0x280 mm/slub.c:3415
 alloc_inode_sb include/linux/fs.h:3263 [inline]
 sock_alloc_inode+0x28/0xc0 net/socket.c:304
 alloc_inode fs/inode.c:264 [inline]
 new_inode_pseudo+0x70/0x1f0 fs/inode.c:1073
 sock_alloc net/socket.c:629 [inline]
 __sock_create+0x12c/0x7c0 net/socket.c:1504
 sock_create net/socket.c:1596 [inline]
 __sys_socket_create net/socket.c:1633 [inline]
 __sys_socket+0xcd/0x1a0 net/socket.c:1661
 __do_sys_socket net/socket.c:1674 [inline]
 __se_sys_socket net/socket.c:1672 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1672
 x64_sys_call+0x449/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:42
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1551 [inline]
 free_pcp_prepare mm/page_alloc.c:1625 [inline]
 free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3589
 free_unref_page+0x8f/0x530 mm/page_alloc.c:3687
 free_the_page mm/page_alloc.c:836 [inline]
 __free_pages+0x67/0x100 mm/page_alloc.c:5957
 __free_slab+0xca/0x1a0 mm/slub.c:2044
 free_slab mm/slub.c:2059 [inline]
 discard_slab mm/slub.c:2065 [inline]
 __unfreeze_partials+0x160/0x190 mm/slub.c:2614
 put_cpu_partial+0xa9/0x100 mm/slub.c:2690
 __slab_free+0x1c4/0x280 mm/slub.c:3589
 do_slab_free mm/slub.c:3666 [inline]
 ___cache_free+0xbf/0xd0 mm/slub.c:3722
 qlink_free mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0xc6/0x140 mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:294
 ____kasan_kmalloc mm/kasan/common.c:345 [inline]
 __kasan_kmalloc+0x24/0xb0 mm/kasan/common.c:388
 kasan_kmalloc include/linux/kasan.h:212 [inline]
 kmalloc_trace+0x40/0xb0 mm/slab_common.c:1033
 kmalloc include/linux/slab.h:563 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 selinux_sk_alloc_security+0x7e/0x1a0 security/selinux/hooks.c:5257
 security_sk_alloc+0x83/0xb0 security/security.c:2331
 sk_prot_alloc+0x108/0x320 net/core/sock.c:2055
 sk_alloc+0x3b/0x460 net/core/sock.c:2109

Memory state around the buggy address:
 ffff888117af3380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888117af3400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888117af3480: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff888117af3500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888117af3580: fb fb fb fb fb fb fb fb fb 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
2025/10/05 06:34 android14-6.1 775e02ce538c 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1-perf KASAN: use-after-free Read in sk_psock_verdict_data_ready
* Struck through repros no longer work on HEAD.