================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2913 Read of size 4 at addr ffff8881136e9000 by task syz-executor/457 CPU: 0 PID: 457 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x71/0x1e0 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:418 kasan_report+0x122/0x150 mm/kasan/report.c:522 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350 ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2913 ext4_evict_inode+0xe58/0x1460 fs/ext4/inode.c:296 evict+0x493/0x890 fs/inode.c:705 iput_final fs/inode.c:1834 [inline] iput+0x620/0x670 fs/inode.c:1860 d_delete_notify include/linux/fsnotify.h:292 [inline] vfs_rmdir+0x3bf/0x500 fs/namei.c:4203 do_rmdir+0x259/0x6a0 fs/namei.c:4251 __do_sys_unlinkat fs/namei.c:4431 [inline] __se_sys_unlinkat fs/namei.c:4425 [inline] __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4425 x64_sys_call+0x79f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:264 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: 0033:0x7fbe99f79457 Code: 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 07 01 00 00 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:00007fff896acc18 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007fbe99f79457 RDX: 0000000000000200 RSI: 00007fff896addc0 RDI: 00000000ffffff9c RBP: 00007fbe99fe77b4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007fff896addc0 R13: 00007fbe99fe77b4 R14: 000000000000b8d7 R15: 00007fff896aff70 Allocated by task 371: 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:3421 [inline] slab_alloc mm/slub.c:3431 [inline] __kmem_cache_alloc_lru mm/slub.c:3438 [inline] kmem_cache_alloc+0x16e/0x330 mm/slub.c:3447 skb_clone+0x1f5/0x380 net/core/skbuff.c:1663 dev_queue_xmit_nit+0x1a5/0xab0 net/core/dev.c:2329 xmit_one net/core/dev.c:3662 [inline] dev_hard_start_xmit+0x16a/0x750 net/core/dev.c:3685 sch_direct_xmit+0x267/0x8d0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3906 [inline] __dev_queue_xmit+0x15f9/0x3420 net/core/dev.c:4311 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_hh_output include/net/neighbour.h:536 [inline] neigh_output include/net/neighbour.h:550 [inline] ip_finish_output2+0xb09/0xef0 net/ipv4/ip_output.c:228 __ip_finish_output+0x172/0x370 net/ipv4/ip_output.c:-1 ip_finish_output+0x31/0x2b0 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip_output+0x1e1/0x360 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:453 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0x11c9/0x1d00 net/ipv4/ip_output.c:532 ip_queue_xmit+0x4d/0x70 net/ipv4/ip_output.c:546 __tcp_transmit_skb+0x1e17/0x3460 net/ipv4/tcp_output.c:1406 tcp_transmit_skb net/ipv4/tcp_output.c:1424 [inline] tcp_write_xmit+0x15fc/0x5fb0 net/ipv4/tcp_output.c:2710 __tcp_push_pending_frames+0x9c/0x2f0 net/ipv4/tcp_output.c:2895 tcp_push+0x48f/0x660 net/ipv4/tcp.c:734 tcp_sendmsg_locked+0x34f1/0x3d90 net/ipv4/tcp.c:1460 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1488 inet_sendmsg+0xb6/0xd0 net/ipv4/af_inet.c:841 sock_sendmsg_nosec net/socket.c:716 [inline] __sock_sendmsg net/socket.c:728 [inline] sock_write_iter+0x2ca/0x3b0 net/socket.c:1133 call_write_iter include/linux/fs.h:2282 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x5db/0xca0 fs/read_write.c:584 ksys_write+0x140/0x240 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:646 x64_sys_call+0x27b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2 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 371: 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:1745 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1771 slab_free mm/slub.c:3686 [inline] kmem_cache_free+0x12d/0x300 mm/slub.c:3711 kfree_skbmem+0x10c/0x180 net/core/skbuff.c:-1 __kfree_skb net/core/skbuff.c:874 [inline] consume_skb+0xb3/0x1f0 net/core/skbuff.c:1038 packet_rcv+0x151/0x1390 net/packet/af_packet.c:2280 dev_queue_xmit_nit+0xa1f/0xab0 net/core/dev.c:2361 xmit_one net/core/dev.c:3662 [inline] dev_hard_start_xmit+0x16a/0x750 net/core/dev.c:3685 sch_direct_xmit+0x267/0x8d0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3906 [inline] __dev_queue_xmit+0x15f9/0x3420 net/core/dev.c:4311 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_hh_output include/net/neighbour.h:536 [inline] neigh_output include/net/neighbour.h:550 [inline] ip_finish_output2+0xb09/0xef0 net/ipv4/ip_output.c:228 __ip_finish_output+0x172/0x370 net/ipv4/ip_output.c:-1 ip_finish_output+0x31/0x2b0 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip_output+0x1e1/0x360 net/ipv4/ip_output.c:430 dst_output include/net/dst.h:453 [inline] ip_local_out net/ipv4/ip_output.c:126 [inline] __ip_queue_xmit+0x11c9/0x1d00 net/ipv4/ip_output.c:532 ip_queue_xmit+0x4d/0x70 net/ipv4/ip_output.c:546 __tcp_transmit_skb+0x1e17/0x3460 net/ipv4/tcp_output.c:1406 tcp_transmit_skb net/ipv4/tcp_output.c:1424 [inline] tcp_write_xmit+0x15fc/0x5fb0 net/ipv4/tcp_output.c:2710 __tcp_push_pending_frames+0x9c/0x2f0 net/ipv4/tcp_output.c:2895 tcp_push+0x48f/0x660 net/ipv4/tcp.c:734 tcp_sendmsg_locked+0x34f1/0x3d90 net/ipv4/tcp.c:1460 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1488 inet_sendmsg+0xb6/0xd0 net/ipv4/af_inet.c:841 sock_sendmsg_nosec net/socket.c:716 [inline] __sock_sendmsg net/socket.c:728 [inline] sock_write_iter+0x2ca/0x3b0 net/socket.c:1133 call_write_iter include/linux/fs.h:2282 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x5db/0xca0 fs/read_write.c:584 ksys_write+0x140/0x240 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:646 x64_sys_call+0x27b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2 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 The buggy address belongs to the object at ffff8881136e9000 which belongs to the cache skbuff_head_cache of size 256 The buggy address is located 0 bytes inside of 256-byte region [ffff8881136e9000, ffff8881136e9100) The buggy address belongs to the physical page: page:ffffea00044dba40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1136e9 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff8881002b0d80 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 371, tgid 371 (sshd-session), ts 38079024090, free_ts 37994081126 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:1962 [inline] new_slab+0x98/0x3d0 mm/slub.c:2015 ___slab_alloc+0x6f6/0xb50 mm/slub.c:3203 __slab_alloc+0x5e/0xa0 mm/slub.c:3302 slab_alloc_node mm/slub.c:3387 [inline] slab_alloc mm/slub.c:3431 [inline] __kmem_cache_alloc_lru mm/slub.c:3438 [inline] kmem_cache_alloc+0x1b0/0x330 mm/slub.c:3447 skb_clone+0x1f5/0x380 net/core/skbuff.c:1663 dev_queue_xmit_nit+0x1a5/0xab0 net/core/dev.c:2329 xmit_one net/core/dev.c:3662 [inline] dev_hard_start_xmit+0x16a/0x750 net/core/dev.c:3685 sch_direct_xmit+0x267/0x8d0 net/sched/sch_generic.c:342 __dev_xmit_skb net/core/dev.c:3906 [inline] __dev_queue_xmit+0x15f9/0x3420 net/core/dev.c:4311 dev_queue_xmit include/linux/netdevice.h:3085 [inline] neigh_hh_output include/net/neighbour.h:536 [inline] neigh_output include/net/neighbour.h:550 [inline] ip_finish_output2+0xb09/0xef0 net/ipv4/ip_output.c:228 __ip_finish_output+0x172/0x370 net/ipv4/ip_output.c:-1 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 __folio_put_small mm/swap.c:97 [inline] __folio_put+0xac/0xe0 mm/swap.c:120 folio_put include/linux/mm.h:1431 [inline] put_page include/linux/mm.h:1483 [inline] anon_pipe_buf_release+0x183/0x200 fs/pipe.c:138 pipe_buf_release include/linux/pipe_fs_i.h:199 [inline] pipe_read+0x55d/0x1000 fs/pipe.c:324 call_read_iter include/linux/fs.h:2276 [inline] new_sync_read fs/read_write.c:389 [inline] vfs_read+0x41e/0x8c0 fs/read_write.c:470 ksys_read+0x140/0x240 fs/read_write.c:613 __do_sys_read fs/read_write.c:623 [inline] __se_sys_read fs/read_write.c:621 [inline] __x64_sys_read+0x7b/0x90 fs/read_write.c:621 x64_sys_call+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:1 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 Memory state around the buggy address: ffff8881136e8f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881136e8f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881136e9000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881136e9080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881136e9100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ================================================================== EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem. EXT4-fs (loop0): unmounting filesystem.