Hello,
syzbot found the following crash on:
HEAD commit: 3fc89857 Linux 4.19.128
git tree: linux-4.19.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=16e43729100000
kernel config:
https://syzkaller.appspot.com/x/.config?x=6c6e6bf14f2aabf
dashboard link:
https://syzkaller.appspot.com/bug?extid=b0fe9558904a8bb778ac
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by:
syzbot+b0fe95...@syzkaller.appspotmail.com
team0 (unregistering): Port device team_slave_0 removed
bond0 (unregistering): Releasing backup interface bond_slave_1
bond0 (unregistering): Releasing backup interface bond_slave_0
bond0 (unregistering): Released all slaves
==================================================================
BUG: KASAN: use-after-free in memmove include/linux/string.h:363 [inline]
BUG: KASAN: use-after-free in ext4_xattr_set_entry+0xb17/0x3340 fs/ext4/xattr.c:1738
Read of size 4 at addr ffff88804570cffe by task syz-fuzzer/6449
CPU: 0 PID: 6449 Comm: syz-fuzzer Not tainted 4.19.128-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2fe lib/dump_stack.c:118
print_address_description.cold+0x54/0x222 mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report mm/kasan/report.c:412 [inline]
kasan_report.cold+0x88/0x2b9 mm/kasan/report.c:396
memmove+0x20/0x50 mm/kasan/kasan.c:293
memmove include/linux/string.h:363 [inline]
ext4_xattr_set_entry+0xb17/0x3340 fs/ext4/xattr.c:1738
ext4_xattr_ibody_set+0x81/0x2a0 fs/ext4/xattr.c:2240
ext4_xattr_set_handle+0x5d2/0x1010 fs/ext4/xattr.c:2396
ext4_initxattrs+0xb5/0x120 fs/ext4/xattr_security.c:43
security_inode_init_security security/security.c:498 [inline]
security_inode_init_security+0x294/0x370 security/security.c:471
__ext4_new_inode+0x3ec5/0x5af0 fs/ext4/ialloc.c:1165
ext4_mkdir+0x396/0xd90 fs/ext4/namei.c:2656
vfs_mkdir+0x423/0x6a0 fs/namei.c:3819
do_mkdirat+0x21e/0x280 fs/namei.c:3842
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4b3cdb
Code: ff e9 69 ff ff ff cc cc cc cc cc cc cc cc cc e8 bb a1 f8 ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30
RSP: 002b:000000c019a42958 EFLAGS: 00000216 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 000000c00002c000 RCX: 00000000004b3cdb
RDX: 00000000000001c0 RSI: 000000c0116b20c0 RDI: ffffffffffffff9c
RBP: 000000c019a429b0 R08: 000000000086f901 R09: 0000000000000001
R10: 000000c0116b20c0 R11: 0000000000000216 R12: ffffffffffffffff
R13: 0000000000000007 R14: 0000000000000006 R15: 0000000000000100
The buggy address belongs to the page:
page:ffffea000115c300 count:2 mapcount:0 mapping:ffff888219f17b20 index:0x408
flags: 0xfffe0000001074(referenced|dirty|lru|active|private)
raw: 00fffe0000001074 ffffea000115d3c8 ffffea000106d988 ffff888219f17b20
raw: 0000000000000408 ffff8880430cfd20 00000002ffffffff ffff88821b6eeb00
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff88821b6eeb00
Memory state around the buggy address:
ffff88804570cf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88804570cf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88804570d000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88804570d080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88804570d100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
---
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