syzbot

EXT4-fs (loop2): 1 truncate cleaned up
EXT4-fs (loop2): mounted filesystem without journal. Opts: init_itable=0x0000000000000000,jqfmt=vfsold,debug_want_extra_isize=0x000000000000006a,nombcache,dioread_lock,debug,,errors=continue
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BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x1339/0x36c0 fs/ext4/xattr.c:1740
Read of size 18446744073709551540 at addr ffff88811ca32070 by task syz.2.62/609

CPU: 1 PID: 609 Comm: syz.2.62 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x280/0x290 mm/kasan/generic.c:189
 memmove+0x2d/0x70 mm/kasan/shadow.c:54
 ext4_xattr_set_entry+0x1339/0x36c0 fs/ext4/xattr.c:1740
 ext4_xattr_block_set+0x92f/0x2a50 fs/ext4/xattr.c:1997
 ext4_xattr_set_handle+0xba5/0x12a0 fs/ext4/xattr.c:2403
 ext4_xattr_set+0x1ec/0x320 fs/ext4/xattr.c:2513
 ext4_xattr_trusted_set+0x3b/0x50 fs/ext4/xattr_trusted.c:37
 __vfs_setxattr+0x42a/0x480 fs/xattr.c:177
 __vfs_setxattr_noperm+0x11e/0x4e0 fs/xattr.c:208
 __vfs_setxattr_locked+0x203/0x220 fs/xattr.c:266
 vfs_setxattr+0x8d/0x1c0 fs/xattr.c:283
 setxattr+0x1a9/0x370 fs/xattr.c:548
 path_setxattr+0x110/0x210 fs/xattr.c:567
 __do_sys_lsetxattr fs/xattr.c:589 [inline]
 __se_sys_lsetxattr fs/xattr.c:585 [inline]
 __x64_sys_lsetxattr+0xc2/0xe0 fs/xattr.c:585
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fe6fd485ec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe6fd2f6038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007fe6fd6dcfa0 RCX: 00007fe6fd485ec9
RDX: 0000200000000640 RSI: 0000200000000300 RDI: 0000200000000100
RBP: 00007fe6fd508f91 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000fe37 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe6fd6dd038 R14: 00007fe6fd6dcfa0 R15: 00007ffdf96211f8

Allocated by task 0:
(stack is not available)

The buggy address belongs to the object at ffff88811ca32000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 112 bytes inside of
 1024-byte region [ffff88811ca32000, ffff88811ca32400)
The buggy address belongs to the page:
page:ffffea0004728c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11ca30
head:ffffea0004728c00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 ffffea000472ae00 0000000500000005 ffff888100042f00
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 0, ts 13678910113, free_ts 13666798226
 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:5370
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1813 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1874
 new_slab_objects mm/slub.c:2632 [inline]
 ___slab_alloc+0x2a6/0x450 mm/slub.c:2796
 __slab_alloc+0x63/0xa0 mm/slub.c:2836
 slab_alloc_node mm/slub.c:2918 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 __kmalloc_track_caller+0x1ef/0x320 mm/slub.c:4541
 __kmalloc_reserve net/core/skbuff.c:144 [inline]
 __alloc_skb+0xdc/0x520 net/core/skbuff.c:212
 __napi_alloc_skb+0x158/0x2e0 net/core/skbuff.c:522
 napi_alloc_skb include/linux/skbuff.h:2975 [inline]
 page_to_skb+0x40/0x8b0 drivers/net/virtio_net.c:432
 receive_mergeable drivers/net/virtio_net.c:1049 [inline]
 receive_buf+0xba1/0x45a0 drivers/net/virtio_net.c:1159
 virtnet_receive drivers/net/virtio_net.c:1451 [inline]
 virtnet_poll+0x4f2/0xef0 drivers/net/virtio_net.c:1560
 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
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_pages_ok+0x7fc/0x820 mm/page_alloc.c:1629
 free_compound_page+0x73/0x90 mm/page_alloc.c:710
 destroy_compound_page include/linux/mm.h:970 [inline]
 __put_compound_page+0x77/0xb0 mm/swap.c:117
 __put_page+0xbd/0xe0 mm/swap.c:133
 put_page include/linux/mm.h:1268 [inline]
 do_exit+0x1a52/0x2480 kernel/exit.c:903
 do_group_exit+0x141/0x310 kernel/exit.c:986
 __do_sys_exit_group kernel/exit.c:997 [inline]
 __se_sys_exit_group kernel/exit.c:995 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:995
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Memory state around the buggy address:
 ffff88811ca31f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88811ca31f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88811ca32000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                             ^
 ffff88811ca32080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88811ca32100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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