loop4: detected capacity change from 0 to 1024 EXT4-fs (loop4): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: none. ================================================================== BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x8e9/0x1e20 fs/ext4/xattr.c:1783 Read of size 18446744073709551588 at addr ffff888078e9b840 by task syz.4.1891/12277 CPU: 0 UID: 0 PID: 12277 Comm: syz.4.1891 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xba/0x230 mm/kasan/report.c:482 kasan_report+0x117/0x150 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200 __asan_memmove+0x29/0x70 mm/kasan/shadow.c:94 ext4_xattr_set_entry+0x8e9/0x1e20 fs/ext4/xattr.c:1783 ext4_xattr_block_set+0x878/0x2ad0 fs/ext4/xattr.c:2030 ext4_xattr_set_handle+0x1286/0x14c0 fs/ext4/xattr.c:2457 ext4_xattr_set+0x255/0x340 fs/ext4/xattr.c:2559 __vfs_setxattr+0x43c/0x480 fs/xattr.c:200 __vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:234 vfs_setxattr+0x16a/0x2e0 fs/xattr.c:321 do_setxattr fs/xattr.c:636 [inline] filename_setxattr+0x281/0x630 fs/xattr.c:665 path_setxattrat+0x3f3/0x430 fs/xattr.c:713 __do_sys_lsetxattr fs/xattr.c:754 [inline] __se_sys_lsetxattr fs/xattr.c:750 [inline] __x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:750 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb0c059aeb9 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:00007fb0c137f028 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd RAX: ffffffffffffffda RBX: 00007fb0c0815fa0 RCX: 00007fb0c059aeb9 RDX: 0000200000000000 RSI: 0000200000000180 RDI: 00002000000001c0 RBP: 00007fb0c0608c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000361 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb0c0816038 R14: 00007fb0c0815fa0 R15: 00007fffccfed458 Allocated by task 12277: kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5657 [inline] __kmalloc_node_track_caller_noprof+0x558/0x7f0 mm/slub.c:5768 kmemdup_noprof+0x2b/0x70 mm/util.c:138 kmemdup_noprof include/linux/fortify-string.h:765 [inline] ext4_xattr_block_set+0x787/0x2ad0 fs/ext4/xattr.c:1978 ext4_xattr_set_handle+0x1286/0x14c0 fs/ext4/xattr.c:2457 ext4_xattr_set+0x255/0x340 fs/ext4/xattr.c:2559 __vfs_setxattr+0x43c/0x480 fs/xattr.c:200 __vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:234 vfs_setxattr+0x16a/0x2e0 fs/xattr.c:321 do_setxattr fs/xattr.c:636 [inline] filename_setxattr+0x281/0x630 fs/xattr.c:665 path_setxattrat+0x3f3/0x430 fs/xattr.c:713 __do_sys_lsetxattr fs/xattr.c:754 [inline] __se_sys_lsetxattr fs/xattr.c:750 [inline] __x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:750 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888078e9b800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 64 bytes inside of 1024-byte region [ffff888078e9b800, ffff888078e9bc00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888078e9d000 pfn:0x78e98 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88813fe26dc0 ffffea0001538600 dead000000000002 raw: ffff888078e9d000 000000008010000d 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88813fe26dc0 ffffea0001538600 dead000000000002 head: ffff888078e9d000 000000008010000d 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001e3a601 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 11825, tgid 11818 (syz.9.1752), ts 362151414268, free_ts 362126139638 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x228/0x280 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3945 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5240 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab+0x86/0x3a0 mm/slub.c:3248 new_slab mm/slub.c:3302 [inline] ___slab_alloc+0xd82/0x1760 mm/slub.c:4656 __slab_alloc+0x65/0x100 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_node_track_caller_noprof+0x5b7/0x7f0 mm/slub.c:5768 kmalloc_reserve+0x136/0x290 net/core/skbuff.c:608 pskb_expand_head+0x19d/0x1300 net/core/skbuff.c:2283 __skb_cow include/linux/skbuff.h:3853 [inline] skb_cow_head include/linux/skbuff.h:3887 [inline] l2tp_xmit_core net/l2tp/l2tp_core.c:1240 [inline] l2tp_xmit_skb+0x2ba/0x16b0 net/l2tp/l2tp_core.c:1327 pppol2tp_sendmsg+0x40a/0x5f0 net/l2tp/l2tp_ppp.c:302 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmmsg+0x27c/0x4e0 net/socket.c:2735 __do_sys_sendmmsg net/socket.c:2762 [inline] __se_sys_sendmmsg net/socket.c:2759 [inline] __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2759 page last free pid 11825 tgid 11818 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0xbf8/0xd70 mm/page_alloc.c:2973 discard_slab mm/slub.c:3346 [inline] __put_partials+0x146/0x170 mm/slub.c:3886 __slab_free+0x294/0x320 mm/slub.c:5956 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_node_noprof+0x427/0x6f0 mm/slub.c:5315 __alloc_skb+0x1d7/0x390 net/core/skbuff.c:679 alloc_skb include/linux/skbuff.h:1383 [inline] sock_wmalloc+0xb2/0x130 net/core/sock.c:2828 pppol2tp_sendmsg+0x183/0x5f0 net/l2tp/l2tp_ppp.c:275 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmmsg+0x27c/0x4e0 net/socket.c:2735 __do_sys_sendmmsg net/socket.c:2762 [inline] __se_sys_sendmmsg net/socket.c:2759 [inline] __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2759 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888078e9b700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888078e9b780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888078e9b800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff888078e9b880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888078e9b900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================