EXT4-fs (loop3): mounted filesystem without journal. Opts: auto_da_alloc,mblk_io_submit,,errors=continue. Quota mode: none. xt_hashlimit: size too large, truncated to 1048576 ================================================================== BUG: KASAN: use-after-free in ext4_xattr_rehash fs/ext4/xattr.c:3135 [inline] BUG: KASAN: use-after-free in ext4_xattr_set_entry+0xe1f/0x3940 fs/ext4/xattr.c:1820 Read of size 4 at addr ffff88810f96b05c by task syz.3.183/1015 CPU: 0 PID: 1015 Comm: syz.3.183 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:308 ext4_xattr_rehash fs/ext4/xattr.c:3135 [inline] ext4_xattr_set_entry+0xe1f/0x3940 fs/ext4/xattr.c:1820 ext4_xattr_block_set+0x4f8/0x2d10 fs/ext4/xattr.c:1924 ext4_xattr_set_handle+0xbc4/0x12b0 fs/ext4/xattr.c:2407 ext4_xattr_set+0x242/0x320 fs/ext4/xattr.c:2508 ext4_xattr_trusted_set+0x3c/0x50 fs/ext4/xattr_trusted.c:38 __vfs_setxattr+0x3e1/0x430 fs/xattr.c:182 __vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216 __vfs_setxattr_locked+0x212/0x230 fs/xattr.c:277 vfs_setxattr+0x167/0x2e0 fs/xattr.c:303 do_setxattr fs/xattr.c:588 [inline] setxattr+0x36c/0x390 fs/xattr.c:611 path_setxattr+0x147/0x290 fs/xattr.c:630 __do_sys_lsetxattr fs/xattr.c:653 [inline] __se_sys_lsetxattr fs/xattr.c:649 [inline] __x64_sys_lsetxattr+0xc2/0xe0 fs/xattr.c:649 x64_sys_call+0x8cc/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:190 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: 0033:0x7fa8bd98d819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa8bc3e8028 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd RAX: ffffffffffffffda RBX: 00007fa8bdc06fa0 RCX: 00007fa8bd98d819 RDX: 0000200000000500 RSI: 0000200000000300 RDI: 0000200000000040 RBP: 00007fa8bda23c91 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000fe37 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa8bdc07038 R14: 00007fa8bdc06fa0 R15: 00007fffdbc00638 Allocated by task 302: 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 skb_clone+0x1cf/0x360 net/core/skbuff.c:1547 do_one_broadcast net/netlink/af_netlink.c:1461 [inline] netlink_broadcast_filtered+0x67a/0x1230 net/netlink/af_netlink.c:1536 netlink_broadcast net/netlink/af_netlink.c:1560 [inline] netlink_sendmsg+0x7fc/0xb80 net/netlink/af_netlink.c:1920 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2435 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2489 __sys_sendmsg net/socket.c:2518 [inline] __do_sys_sendmsg net/socket.c:2527 [inline] __se_sys_sendmsg net/socket.c:2525 [inline] __x64_sys_sendmsg+0x206/0x2f0 net/socket.c:2525 x64_sys_call+0x4b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47 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 302: 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 do_one_broadcast net/netlink/af_netlink.c:-1 [inline] netlink_broadcast_filtered+0x740/0x1230 net/netlink/af_netlink.c:1536 netlink_broadcast net/netlink/af_netlink.c:1560 [inline] netlink_sendmsg+0x7fc/0xb80 net/netlink/af_netlink.c:1920 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2435 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2489 __sys_sendmsg net/socket.c:2518 [inline] __do_sys_sendmsg net/socket.c:2527 [inline] __se_sys_sendmsg net/socket.c:2525 [inline] __x64_sys_sendmsg+0x206/0x2f0 net/socket.c:2525 x64_sys_call+0x4b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47 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 The buggy address belongs to the object at ffff88810f96b000 which belongs to the cache skbuff_head_cache of size 248 The buggy address is located 92 bytes inside of 248-byte region [ffff88810f96b000, ffff88810f96b0f8) The buggy address belongs to the page: page:ffffea00043e5ac0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10f96b flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 0000000100000001 ffff8881081ab380 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 404, ts 28026912467, free_ts 27980983997 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:5822 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 skb_clone+0x1cf/0x360 net/core/skbuff.c:1547 do_one_broadcast net/netlink/af_netlink.c:1461 [inline] netlink_broadcast_filtered+0x67a/0x1230 net/netlink/af_netlink.c:1536 netlink_broadcast+0x3a/0x50 net/netlink/af_netlink.c:1560 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_uevent+0x1d/0x30 lib/kobject_uevent.c:657 __loop_clr_fd+0x944/0xd30 drivers/block/loop.c:1425 loop_clr_fd drivers/block/loop.c:1513 [inline] lo_ioctl+0x1475/0x2370 drivers/block/loop.c:1869 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:5898 free_pages+0x82/0x90 mm/page_alloc.c:5909 tlb_batch_list_free mm/mmu_gather.c:61 [inline] tlb_finish_mmu+0x258/0x310 mm/mmu_gather.c:341 exit_mmap+0x43b/0x8b0 mm/mmap.c:3248 __mmput+0x93/0x320 kernel/fork.c:1180 mmput+0x50/0x150 kernel/fork.c:1203 exit_mm kernel/exit.c:554 [inline] do_exit+0x9f2/0x27e0 kernel/exit.c:876 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 irqentry_exit_to_user_mode+0x9/0x10 kernel/entry/common.c:320 irqentry_exit+0x12/0x40 kernel/entry/common.c:411 Memory state around the buggy address: ffff88810f96af00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88810f96af80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88810f96b000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88810f96b080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc ffff88810f96b100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ==================================================================