================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xbe3/0xbf0 fs/ext4/xattr.c:2909 Read of size 4 at addr ffff888113071000 by task syz-executor/472 CPU: 1 PID: 472 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:77 dump_stack_lvl+0x169/0x1d8 lib/dump_stack.c:118 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:435 [inline] kasan_report+0xe2/0x130 mm/kasan/report.c:452 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_xattr_delete_inode+0xbe3/0xbf0 fs/ext4/xattr.c:2909 ext4_evict_inode+0x10d3/0x1760 fs/ext4/inode.c:300 evict+0x478/0x910 fs/inode.c:612 iput_final fs/inode.c:1736 [inline] iput+0x638/0x7c0 fs/inode.c:1762 d_delete_notify include/linux/fsnotify.h:267 [inline] vfs_rmdir+0x2bd/0x3e0 fs/namei.c:3865 do_rmdir+0x218/0x620 fs/namei.c:3912 __do_sys_unlinkat fs/namei.c:4076 [inline] __se_sys_unlinkat fs/namei.c:4070 [inline] __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4070 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7fc376e36707 Code: 73 01 c3 48 c7 c1 b0 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffed2616588 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007fc376e36707 RDX: 0000000000000200 RSI: 00007ffed2617730 RDI: 00000000ffffff9c RBP: 00007fc376e936c6 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffed2617730 R13: 00007fc376e936c6 R14: 000000000000a3b2 R15: 0000000000000000 Allocated by task 430: 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+0xbd/0xf0 mm/kasan/common.c:463 kasan_slab_alloc include/linux/kasan.h:244 [inline] slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580 slab_alloc_node mm/slub.c:2952 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x165/0x2e0 mm/slub.c:2965 skb_clone+0x1e9/0x380 net/core/skbuff.c:1467 do_one_broadcast net/netlink/af_netlink.c:1453 [inline] netlink_broadcast_filtered+0x695/0x1270 net/netlink/af_netlink.c:1528 netlink_broadcast net/netlink/af_netlink.c:1552 [inline] netlink_sendmsg+0x846/0xb30 net/netlink/af_netlink.c:1912 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430 __sys_sendmsg net/socket.c:2459 [inline] __do_sys_sendmsg net/socket.c:2468 [inline] __se_sys_sendmsg net/socket.c:2466 [inline] __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2466 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Freed by task 430: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4a/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0x125/0x160 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:1600 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626 slab_free mm/slub.c:3208 [inline] kmem_cache_free+0x100/0x2d0 mm/slub.c:3224 kfree_skbmem+0x10c/0x180 net/core/skbuff.c:-1 __kfree_skb net/core/skbuff.c:695 [inline] kfree_skb+0xc1/0x2f0 net/core/skbuff.c:713 do_one_broadcast net/netlink/af_netlink.c:-1 [inline] netlink_broadcast_filtered+0x75b/0x1270 net/netlink/af_netlink.c:1528 netlink_broadcast net/netlink/af_netlink.c:1552 [inline] netlink_sendmsg+0x846/0xb30 net/netlink/af_netlink.c:1912 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430 __sys_sendmsg net/socket.c:2459 [inline] __do_sys_sendmsg net/socket.c:2468 [inline] __se_sys_sendmsg net/socket.c:2466 [inline] __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2466 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb The buggy address belongs to the object at ffff888113071000 which belongs to the cache skbuff_head_cache of size 248 The buggy address is located 0 bytes inside of 248-byte region [ffff888113071000, ffff8881130710f8) The buggy address belongs to the page: page:ffffea00044c1c40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x113071 flags: 0x4000000000000200(slab) raw: 4000000000000200 ffffea000446bdc0 0000000800000008 ffff888107d94d80 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 95, ts 4633499332, free_ts 4623062023 set_page_owner include/linux/page_owner.h:35 [inline] post_alloc_hook mm/page_alloc.c:2456 [inline] prep_new_page+0x179/0x180 mm/page_alloc.c:2462 get_page_from_freelist+0x2235/0x23d0 mm/page_alloc.c:4254 __alloc_pages_nodemask+0x268/0x5f0 mm/page_alloc.c:5370 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1813 [inline] new_slab+0x84/0x3f0 mm/slub.c:1874 new_slab_objects mm/slub.c:2632 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2796 __slab_alloc+0x63/0xa0 mm/slub.c:2836 slab_alloc_node mm/slub.c:2918 [inline] slab_alloc mm/slub.c:2960 [inline] kmem_cache_alloc+0x1af/0x2e0 mm/slub.c:2965 kmem_cache_alloc_node include/linux/slab.h:423 [inline] __alloc_skb+0x9e/0x520 net/core/skbuff.c:200 alloc_skb include/linux/skbuff.h:1126 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1178 [inline] netlink_sendmsg+0x5f6/0xb30 net/netlink/af_netlink.c:1889 sock_sendmsg_nosec net/socket.c:652 [inline] __sock_sendmsg net/socket.c:664 [inline] ____sys_sendmsg+0x5a2/0x8c0 net/socket.c:2376 ___sys_sendmsg+0x1f0/0x260 net/socket.c:2430 __sys_sendmsg net/socket.c:2459 [inline] __do_sys_sendmsg net/socket.c:2468 [inline] __se_sys_sendmsg net/socket.c:2466 [inline] __x64_sys_sendmsg+0x1e2/0x2a0 net/socket.c:2466 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb 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+0x2b7/0x2d0 mm/page_alloc.c:3336 free_unref_page_list+0x12e/0x9b0 mm/page_alloc.c:3443 release_pages+0xe38/0xe80 mm/swap.c:1103 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:356 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] tlb_flush_mmu_free mm/mmu_gather.c:240 [inline] tlb_flush_mmu mm/mmu_gather.c:247 [inline] tlb_finish_mmu+0x175/0x300 mm/mmu_gather.c:326 exit_mmap+0x2fc/0x540 mm/mmap.c:3387 __mmput+0x93/0x2f0 kernel/fork.c:1153 mmput+0x4e/0x150 kernel/fork.c:1176 exit_mm kernel/exit.c:539 [inline] do_exit+0x9ae/0x2480 kernel/exit.c:859 do_group_exit+0x141/0x310 kernel/exit.c:986 __do_sys_exit_group kernel/exit.c:997 [inline] __se_sys_exit_group kernel/exit.c:995 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:995 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Memory state around the buggy address: ffff888113070f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888113070f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888113071000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888113071080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc ffff888113071100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ==================================================================