================================================================== BUG: KASAN: use-after-free in unix_stream_read_actor+0x9e/0xa0 net/unix/af_unix.c:2809 Read of size 4 at addr ffff888019c59a44 by task syz-executor.0/7934 CPU: 1 PID: 7934 Comm: syz-executor.0 Not tainted 5.15.138-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description+0x63/0x3b0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0x16b/0x1c0 mm/kasan/report.c:451 unix_stream_read_actor+0x9e/0xa0 net/unix/af_unix.c:2809 unix_stream_recv_urg+0x1bb/0x300 net/unix/af_unix.c:2535 unix_stream_read_generic+0x21ab/0x22a0 net/unix/af_unix.c:2615 unix_stream_recvmsg+0x22d/0x2c0 net/unix/af_unix.c:2847 ____sys_recvmsg+0x286/0x530 ___sys_recvmsg+0x1ec/0x690 net/socket.c:2690 __sys_recvmsg net/socket.c:2720 [inline] __do_sys_recvmsg net/socket.c:2730 [inline] __se_sys_recvmsg net/socket.c:2727 [inline] __x64_sys_recvmsg+0x1dc/0x2b0 net/socket.c:2727 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7febf6a30ae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007febf5d700c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 00007febf6b50120 RCX: 00007febf6a30ae9 RDX: 0000000040010083 RSI: 0000000020000140 RDI: 0000000000000004 RBP: 00007febf6a7c47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007febf6b50120 R15: 00007ffe73701ee8 Allocated by task 7933: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] kmem_cache_alloc_node+0x121/0x2c0 mm/slub.c:3256 __alloc_skb+0xdd/0x590 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1167 [inline] alloc_skb_with_frags+0xa3/0x780 net/core/skbuff.c:6132 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2512 queue_oob+0xfd/0x8d0 net/unix/af_unix.c:1980 unix_stream_sendmsg+0xe0a/0x1070 net/unix/af_unix.c:2117 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2429 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2483 __sys_sendmsg net/socket.c:2512 [inline] __do_sys_sendmsg net/socket.c:2521 [inline] __se_sys_sendmsg+0x19a/0x260 net/socket.c:2519 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 7933: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x80 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xdd/0x160 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kmem_cache_free+0x91/0x1f0 mm/slub.c:3515 queue_oob+0x524/0x8d0 net/unix/af_unix.c:2011 unix_stream_sendmsg+0xe0a/0x1070 net/unix/af_unix.c:2117 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2429 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2483 __sys_sendmsg net/socket.c:2512 [inline] __do_sys_sendmsg net/socket.c:2521 [inline] __se_sys_sendmsg+0x19a/0x260 net/socket.c:2519 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff888019c59a00 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 68 bytes inside of 232-byte region [ffff888019c59a00, ffff888019c59ae8) The buggy address belongs to the page: page:ffffea0000671640 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x19c59 memcg:ffff88801c498d01 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 dead000000000100 dead000000000122 ffff8881449cf500 raw: 0000000000000000 00000000000c000c 00000001ffffffff ffff88801c498d01 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 5041, ts 98970725553, free_ts 98918085064 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xbb/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] kmem_cache_alloc_node+0x1ba/0x2c0 mm/slub.c:3256 __alloc_skb+0xdd/0x590 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1167 [inline] alloc_skb_with_frags+0xa3/0x780 net/core/skbuff.c:6132 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2512 queue_oob+0xfd/0x8d0 net/unix/af_unix.c:1980 unix_stream_sendmsg+0xe0a/0x1070 net/unix/af_unix.c:2117 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2429 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2483 __sys_sendmsg net/socket.c:2512 [inline] __do_sys_sendmsg net/socket.c:2521 [inline] __se_sys_sendmsg+0x19a/0x260 net/socket.c:2519 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0xc34/0xcf0 mm/page_alloc.c:3317 free_unref_page+0x95/0x2d0 mm/page_alloc.c:3396 do_slab_free mm/slub.c:3487 [inline] ___cache_free+0xe3/0x100 mm/slub.c:3506 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 inotify_new_watch fs/notify/inotify/inotify_user.c:581 [inline] inotify_update_watch fs/notify/inotify/inotify_user.c:628 [inline] __do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:766 [inline] __se_sys_inotify_add_watch+0x5be/0xb20 fs/notify/inotify/inotify_user.c:709 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb Memory state around the buggy address: ffff888019c59900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888019c59980: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc >ffff888019c59a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888019c59a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff888019c59b00: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ==================================================================