================================================================== BUG: KASAN: slab-out-of-bounds in ext4_htree_fill_tree+0x10f5/0x1160 fs/ext4/namei.c:1246 Read of size 1 at addr ffff888111723c67 by task syz-executor/476 CPU: 0 PID: 476 Comm: syz-executor Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 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_load1_noabort+0x14/0x20 mm/kasan/report_generic.c:306 ext4_htree_fill_tree+0x10f5/0x1160 fs/ext4/namei.c:1246 ext4_dx_readdir fs/ext4/dir.c:609 [inline] ext4_readdir+0x2cdb/0x3b20 fs/ext4/dir.c:145 iterate_dir+0x260/0x600 fs/readdir.c:-1 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0xf2/0x250 fs/readdir.c:354 __x64_sys_getdents64+0x7b/0x90 fs/readdir.c:354 x64_sys_call+0x592/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:218 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: 0033:0x7fae534f72b3 Code: c7 c0 e8 ff ff ff 64 c7 00 16 00 00 00 31 c0 eb 9e e8 81 9b fd ff 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 e8 ff ff ff f7 d8 RSP: 002b:00007ffc16888648 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 0000555593fbd910 RCX: 00007fae534f72b3 RDX: 0000000000008000 RSI: 0000555593fbd940 RDI: 0000000000000005 RBP: 0000555593fbd940 R08: 0000000000028701 R09: 0000000000000001 R10: 00007fae536cbca0 R11: 0000000000000293 R12: 0000555593fbd914 R13: ffffffffffffffe8 R14: 0000000000000010 R15: 00007ffc1688a8f0 Allocated by task 342: 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:3245 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0xf7/0x260 mm/slub.c:3260 kmem_cache_alloc_node include/linux/slab.h:492 [inline] __alloc_skb+0xe0/0x740 net/core/skbuff.c:416 alloc_skb include/linux/skbuff.h:1183 [inline] mld_newpack+0x142/0x9e0 net/ipv6/mcast.c:1745 add_grhead+0x5e/0x290 net/ipv6/mcast.c:1856 add_grec+0xd41/0x1100 net/ipv6/mcast.c:1994 mld_send_initial_cr net/ipv6/mcast.c:2241 [inline] ipv6_mc_dad_complete+0x25a/0x610 net/ipv6/mcast.c:2252 addrconf_dad_completed+0x73b/0xe20 net/ipv6/addrconf.c:4279 addrconf_dad_work+0xc91/0x1560 net/ipv6/addrconf.c:-1 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Freed by task 342: 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:1728 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1754 slab_free mm/slub.c:3526 [inline] kmem_cache_free+0x100/0x320 mm/slub.c:3544 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 ip6_mc_input+0x235/0x2a0 net/ipv6/ip6_input.c:572 dst_input include/net/dst.h:463 [inline] ip6_rcv_finish+0x18d/0x360 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:305 [inline] ipv6_rcv+0xed/0x230 net/ipv6/ip6_input.c:300 __netif_receive_skb_one_core net/core/dev.c:5546 [inline] __netif_receive_skb+0xc8/0x280 net/core/dev.c:5660 process_backlog+0x368/0x600 net/core/dev.c:6537 __napi_poll+0xbe/0x590 net/core/dev.c:7096 napi_poll net/core/dev.c:7163 [inline] net_rx_action+0x389/0x900 net/core/dev.c:7253 handle_softirqs+0x250/0x560 kernel/softirq.c:583 __do_softirq+0xb/0xd kernel/softirq.c:621 The buggy address belongs to the object at ffff888111723b40 which belongs to the cache skbuff_head_cache of size 248 The buggy address is located 47 bytes to the right of 248-byte region [ffff888111723b40, ffff888111723c38) The buggy address belongs to the page: page:ffffea000445c8c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x111723 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff8881081ab500 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 342, ts 48528135698, free_ts 47051054372 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+0x2d3a/0x2dc0 mm/page_alloc.c:4485 __alloc_pages+0x1a2/0x460 mm/page_alloc.c:5808 alloc_slab_page mm/slub.c:-1 [inline] allocate_slab mm/slub.c:1937 [inline] new_slab+0xa1/0x4d0 mm/slub.c:2000 ___slab_alloc+0x381/0x810 mm/slub.c:3033 __slab_alloc+0x49/0x90 mm/slub.c:3120 slab_alloc_node mm/slub.c:3211 [inline] slab_alloc mm/slub.c:3255 [inline] kmem_cache_alloc+0x138/0x260 mm/slub.c:3260 kmem_cache_alloc_node include/linux/slab.h:492 [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] inet6_ifa_notify net/ipv6/addrconf.c:5540 [inline] __ipv6_ifa_notify+0x200/0xe70 net/ipv6/addrconf.c:6195 ipv6_ifa_notify net/ipv6/addrconf.c:6247 [inline] addrconf_dad_completed+0x180/0xe20 net/ipv6/addrconf.c:4260 addrconf_dad_work+0xc91/0x1560 net/ipv6/addrconf.c:-1 process_one_work+0x6be/0xba0 kernel/workqueue.c:2325 worker_thread+0xa59/0x1200 kernel/workqueue.c:2472 kthread+0x411/0x500 kernel/kthread.c:337 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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+0xae/0x540 mm/page_alloc.c:3616 free_the_page mm/page_alloc.c:805 [inline] __free_pages+0x6c/0x100 mm/page_alloc.c:5884 __vunmap+0x86d/0xa00 mm/vmalloc.c:2660 __vfree mm/vmalloc.c:2709 [inline] vfree+0x8b/0xc0 mm/vmalloc.c:2740 kcov_put kernel/kcov.c:417 [inline] kcov_close+0x2b/0x50 kernel/kcov.c:519 __fput+0x20b/0x8b0 fs/file_table.c:311 ____fput+0x15/0x20 fs/file_table.c:339 task_work_run+0x127/0x190 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0xa9e/0x27e0 kernel/exit.c:889 do_group_exit+0x141/0x310 kernel/exit.c:1003 get_signal+0x66a/0x1480 kernel/signal.c:2907 arch_do_signal_or_restart+0xdf/0x11c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0xa7/0xe0 kernel/entry/common.c:178 exit_to_user_mode_prepare+0x87/0xd0 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:307 Memory state around the buggy address: ffff888111723b00: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff888111723b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888111723c00: fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc ^ ffff888111723c80: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888111723d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc 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