================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2920 Read of size 4 at addr ffff88812b845000 by task syz-executor/456 CPU: 0 PID: 456 Comm: syz-executor Not tainted 5.15.185-syzkaller-1080790-g32c443bd6d40 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:427 [inline] kasan_report+0xf1/0x140 mm/kasan/report.c:444 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_xattr_delete_inode+0xba6/0xbb0 fs/ext4/xattr.c:2920 ext4_evict_inode+0xe44/0x1450 fs/ext4/inode.c:300 evict+0x485/0x870 fs/inode.c:650 iput_final fs/inode.c:1779 [inline] iput+0x635/0x7c0 fs/inode.c:1805 d_delete_notify include/linux/fsnotify.h:278 [inline] vfs_rmdir+0x33f/0x460 fs/namei.c:4162 do_rmdir+0x259/0x6a0 fs/namei.c:4210 __do_sys_unlinkat fs/namei.c:4390 [inline] __se_sys_unlinkat fs/namei.c:4384 [inline] __x64_sys_unlinkat+0xc7/0xf0 fs/namei.c:4384 x64_sys_call+0x4c0/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:264 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f787f8855d7 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:00007ffdf6d754e8 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f787f8855d7 RDX: 0000000000000200 RSI: 00007ffdf6d76690 RDI: 00000000ffffff9c RBP: 00007f787f8f8134 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffdf6d76690 R13: 00007f787f8f8134 R14: 000000000000cd0e R15: 00007ffdf6d78840 Allocated by task 467: 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:433 [inline] __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:466 kasan_slab_alloc include/linux/kasan.h:217 [inline] slab_post_alloc_hook+0x4f/0x2b0 mm/slab.h:550 slab_alloc_node mm/slub.c:3240 [inline] slab_alloc mm/slub.c:3250 [inline] kmem_cache_alloc+0xf7/0x260 mm/slub.c:3255 kmem_cache_alloc_node include/linux/slab.h:489 [inline] __alloc_skb+0xe0/0x740 net/core/skbuff.c:416 alloc_skb include/linux/skbuff.h:1183 [inline] nlmsg_new include/net/netlink.h:953 [inline] audit_buffer_alloc kernel/audit.c:1799 [inline] audit_log_start+0x3c7/0x8b0 kernel/audit.c:1917 common_lsm_audit+0xd1/0x1600 security/lsm_audit.c:457 slow_avc_audit+0x1ac/0x220 security/selinux/avc.c:802 avc_audit security/selinux/include/avc.h:135 [inline] avc_has_perm+0x1e6/0x240 security/selinux/avc.c:1190 superblock_has_perm security/selinux/hooks.c:1993 [inline] selinux_sb_kern_mount+0x168/0x1f0 security/selinux/hooks.c:2816 security_sb_kern_mount+0x62/0x90 security/security.c:962 do_new_mount_fc fs/namespace.c:2934 [inline] do_new_mount+0x2d1/0xa20 fs/namespace.c:3016 path_mount+0x675/0x1020 fs/namespace.c:3344 do_mount fs/namespace.c:3357 [inline] __do_sys_mount fs/namespace.c:3565 [inline] __se_sys_mount+0x318/0x380 fs/namespace.c:3542 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3542 x64_sys_call+0x6bf/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 30: 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:365 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:373 kasan_slab_free include/linux/kasan.h:193 [inline] slab_free_hook mm/slub.c:1723 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1749 slab_free mm/slub.c:3521 [inline] kmem_cache_free+0x100/0x320 mm/slub.c:3539 kfree_skbmem+0x10c/0x180 net/core/skbuff.c:-1 __kfree_skb net/core/skbuff.c:758 [inline] kfree_skb_reason net/core/skbuff.c:778 [inline] kfree_skb+0xc1/0x2f0 net/core/skbuff.c:792 kauditd_hold_skb+0x116/0x210 kernel/audit.c:614 kauditd_send_queue+0x289/0x2d0 kernel/audit.c:769 kauditd_thread+0x4e2/0x860 kernel/audit.c:893 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff88812b845000 which belongs to the cache skbuff_head_cache of size 248 The buggy address is located 0 bytes inside of 248-byte region [ffff88812b845000, ffff88812b8450f8) The buggy address belongs to the page: page:ffffea0004ae1140 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12b845 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff8881081abb00 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 20, ts 52529960033, free_ts 52072408850 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x192/0x1b0 mm/page_alloc.c:2605 prep_new_page+0x1c/0x110 mm/page_alloc.c:2611 get_page_from_freelist+0x2cc5/0x2d50 mm/page_alloc.c:4485 __alloc_pages+0x18f/0x440 mm/page_alloc.c:5795 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1932 [inline] new_slab+0xa1/0x4d0 mm/slub.c:1995 ___slab_alloc+0x381/0x810 mm/slub.c:3028 __slab_alloc+0x49/0x90 mm/slub.c:3115 slab_alloc_node mm/slub.c:3206 [inline] slab_alloc mm/slub.c:3250 [inline] kmem_cache_alloc+0x138/0x260 mm/slub.c:3255 kmem_cache_alloc_node include/linux/slab.h:489 [inline] __alloc_skb+0xe0/0x740 net/core/skbuff.c:416 alloc_skb include/linux/skbuff.h:1183 [inline] mld_newpack+0x13a/0x9d0 net/ipv6/mcast.c:1746 add_grhead+0x5e/0x290 net/ipv6/mcast.c:1857 add_grec+0xd41/0x1100 net/ipv6/mcast.c:1995 mld_send_cr net/ipv6/mcast.c:2121 [inline] mld_ifc_work+0x75d/0xbe0 net/ipv6/mcast.c:2659 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1472 [inline] free_pcp_prepare mm/page_alloc.c:1544 [inline] free_unref_page_prepare+0x542/0x550 mm/page_alloc.c:3534 free_unref_page+0xa2/0x550 mm/page_alloc.c:3616 free_the_page mm/page_alloc.c:805 [inline] __free_pages+0x6c/0x100 mm/page_alloc.c:5871 free_pages+0x82/0x90 mm/page_alloc.c:5882 kasan_depopulate_vmalloc_pte+0x6b/0x90 mm/kasan/shadow.c:354 apply_to_pte_range mm/memory.c:2643 [inline] apply_to_pmd_range mm/memory.c:2687 [inline] apply_to_pud_range mm/memory.c:2723 [inline] apply_to_p4d_range mm/memory.c:2759 [inline] __apply_to_page_range+0x8b0/0xbf0 mm/memory.c:2795 apply_to_existing_page_range+0x38/0x50 mm/memory.c:2828 kasan_release_vmalloc+0x97/0xb0 mm/kasan/shadow.c:464 __purge_vmap_area_lazy+0xc05/0x1840 mm/vmalloc.c:1715 _vm_unmap_aliases+0x2fd/0x380 mm/vmalloc.c:2118 vm_unmap_aliases+0x19/0x20 mm/vmalloc.c:2141 change_page_attr_set_clr+0x311/0xc10 arch/x86/mm/pat/set_memory.c:1740 change_page_attr_clear arch/x86/mm/pat/set_memory.c:1797 [inline] set_memory_ro+0x89/0xd0 arch/x86/mm/pat/set_memory.c:1943 bpf_jit_binary_lock_ro include/linux/filter.h:899 [inline] bpf_int_jit_compile+0xc493/0xcc60 arch/x86/net/bpf_jit_comp.c:2478 bpf_prog_select_runtime+0x6f1/0x9f0 kernel/bpf/core.c:1934 bpf_migrate_filter net/core/filter.c:1307 [inline] bpf_prepare_filter+0x1014/0x11c0 net/core/filter.c:1355 Memory state around the buggy address: ffff88812b844f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88812b844f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88812b845000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88812b845080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc ffff88812b845100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ==================================================================