================================================================== BUG: KASAN: use-after-free in ext4_xattr_delete_inode+0xbe3/0xbf0 fs/ext4/xattr.c:2909 Read of size 4 at addr ffff88810ee9c000 by task syz-executor/476 CPU: 1 PID: 476 Comm: syz-executor Not tainted 5.10.240-syzkaller-1008085-g1154f779f3f3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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+0x106f/0x16e0 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: 0033:0x7f9c925e9707 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:00007ffec5d6b018 EFLAGS: 00000207 ORIG_RAX: 0000000000000107 RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 00007f9c925e9707 RDX: 0000000000000200 RSI: 00007ffec5d6c1c0 RDI: 00000000ffffff9c RBP: 00007f9c926466c6 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000207 R12: 00007ffec5d6c1c0 R13: 00007f9c926466c6 R14: 000000000000be3c R15: 0000000000000000 Allocated by task 0: 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:583 slab_alloc_node mm/slub.c:2947 [inline] slab_alloc mm/slub.c:2955 [inline] kmem_cache_alloc+0x165/0x2e0 mm/slub.c:2960 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] alloc_skb_with_frags+0xa2/0x560 net/core/skbuff.c:5993 sock_alloc_send_pskb+0x853/0x980 net/core/sock.c:2388 sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2405 mld_newpack+0x193/0x9a0 net/ipv6/mcast.c:1604 add_grhead+0x5e/0x290 net/ipv6/mcast.c:1707 add_grec+0xd43/0x1100 net/ipv6/mcast.c:1838 mld_send_cr net/ipv6/mcast.c:1964 [inline] mld_ifc_timer_expire+0x770/0xc50 net/ipv6/mcast.c:2471 call_timer_fn+0x38/0x290 kernel/time/timer.c:1450 expire_timers kernel/time/timer.c:1495 [inline] __run_timers+0x639/0x9a0 kernel/time/timer.c:1789 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1802 __do_softirq+0x255/0x563 kernel/softirq.c:309 Freed by task 0: 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:1595 [inline] slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1621 slab_free mm/slub.c:3203 [inline] kmem_cache_free+0x100/0x2d0 mm/slub.c:3219 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 ip6_mc_input+0x235/0x2a0 net/ipv6/ip6_input.c:574 dst_input include/net/dst.h:461 [inline] ip6_rcv_finish+0x18c/0x360 net/ipv6/ip6_input.c:80 NF_HOOK include/linux/netfilter.h:299 [inline] ipv6_rcv+0xec/0x210 net/ipv6/ip6_input.c:301 __netif_receive_skb_one_core net/core/dev.c:5402 [inline] __netif_receive_skb+0xc8/0x280 net/core/dev.c:5516 process_backlog+0x368/0x600 net/core/dev.c:6423 napi_poll net/core/dev.c:6874 [inline] net_rx_action+0x432/0xdd0 net/core/dev.c:6944 __do_softirq+0x255/0x563 kernel/softirq.c:309 The buggy address belongs to the object at ffff88810ee9c000 which belongs to the cache skbuff_head_cache of size 248 The buggy address is located 0 bytes inside of 248-byte region [ffff88810ee9c000, ffff88810ee9c0f8) The buggy address belongs to the page: page:ffffea00043ba700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10ee9c flags: 0x4000000000000200(slab) raw: 4000000000000200 ffffea00043db4c0 0000000700000007 ffff888107d95980 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 96, ts 5810019822, free_ts 5809958363 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:5357 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1808 [inline] new_slab+0x84/0x3f0 mm/slub.c:1869 new_slab_objects mm/slub.c:2627 [inline] ___slab_alloc+0x2a6/0x450 mm/slub.c:2791 __slab_alloc+0x63/0xa0 mm/slub.c:2831 slab_alloc_node mm/slub.c:2913 [inline] slab_alloc mm/slub.c:2955 [inline] kmem_cache_alloc+0x1af/0x2e0 mm/slub.c:2960 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+0x3a/0x50 net/netlink/af_netlink.c:1552 uevent_net_broadcast_untagged lib/kobject_uevent.c:331 [inline] kobject_uevent_net_broadcast+0x3bd/0x5a0 lib/kobject_uevent.c:409 kobject_uevent_env+0x52e/0x700 lib/kobject_uevent.c:608 kobject_synth_uevent+0x520/0xaf0 lib/kobject_uevent.c:208 uevent_store+0x4b/0x70 drivers/base/bus.c:587 drv_attr_store+0x79/0xa0 drivers/base/bus.c:77 sysfs_kf_write+0x129/0x150 fs/sysfs/file.c:139 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 mm/page_alloc.c:3391 [inline] free_the_page mm/page_alloc.c:5416 [inline] __free_pages+0x14b/0x380 mm/page_alloc.c:5427 free_pages+0x82/0x90 mm/page_alloc.c:5438 selinux_genfs_get_sid+0x20b/0x250 security/selinux/hooks.c:1326 inode_doinit_with_dentry+0x86d/0xd70 security/selinux/hooks.c:1523 selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:6389 security_d_instantiate+0x9e/0xf0 security/security.c:1980 d_splice_alias+0x6d/0x390 fs/dcache.c:3036 kernfs_iop_lookup+0x2c5/0x310 fs/kernfs/dir.c:1178 lookup_open fs/namei.c:3226 [inline] open_last_lookups fs/namei.c:3317 [inline] path_openat+0x1127/0x3160 fs/namei.c:3506 do_filp_open+0x1b3/0x3e0 fs/namei.c:3536 do_sys_openat2+0x14c/0x6d0 fs/open.c:1217 do_sys_open fs/open.c:1233 [inline] __do_sys_openat fs/open.c:1249 [inline] __se_sys_openat fs/open.c:1244 [inline] __x64_sys_openat+0x136/0x160 fs/open.c:1244 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x61/0xcb Memory state around the buggy address: ffff88810ee9bf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88810ee9bf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88810ee9c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810ee9c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc ffff88810ee9c100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ==================================================================