KASAN: slab-out-of-bounds Read in reiserfs_xattr

KASAN: slab-out-of-bounds Read in reiserfs_xattr_get
Status: upstream: reported on 2021/04/13 05:55
Reported-by: syzbot+72ba979b6681c3369db4@syzkaller.appspotmail.com
First crash: 19d, last: 9d16h

Sample crash report:

loop0: detected capacity change from 0 to 65534
==================================================================
BUG: KASAN: slab-out-of-bounds in reiserfs_xattr_get+0xe0/0x590 fs/reiserfs/xattr.c:681
Read of size 8 at addr ffff88802b424f98 by task syz-executor.0/2277

CPU: 0 PID: 2277 Comm: syz-executor.0 Not tainted 5.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x176/0x24e lib/dump_stack.c:120
 print_address_description+0x5f/0x3a0 mm/kasan/report.c:232
 __kasan_report mm/kasan/report.c:399 [inline]
 kasan_report+0x15c/0x200 mm/kasan/report.c:416
 reiserfs_xattr_get+0xe0/0x590 fs/reiserfs/xattr.c:681
 reiserfs_get_acl+0x63/0x670 fs/reiserfs/xattr_acl.c:211
 get_acl+0x152/0x2e0 fs/posix_acl.c:141
 check_acl fs/namei.c:294 [inline]
 acl_permission_check fs/namei.c:339 [inline]
 generic_permission+0x2ed/0x5b0 fs/namei.c:392
 do_inode_permission fs/namei.c:446 [inline]
 inode_permission+0x28e/0x500 fs/namei.c:513
 may_open+0x228/0x3e0 fs/namei.c:2985
 do_open fs/namei.c:3365 [inline]
 path_openat+0x2697/0x3860 fs/namei.c:3500
 do_filp_open+0x1a3/0x3b0 fs/namei.c:3527
 do_sys_openat2+0xba/0x380 fs/open.c:1187
 do_sys_open fs/open.c:1203 [inline]
 __do_sys_openat fs/open.c:1219 [inline]
 __se_sys_openat fs/open.c:1214 [inline]
 __x64_sys_openat+0x1c8/0x1f0 fs/open.c:1214
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x419544
Code: 84 00 00 00 00 00 44 89 54 24 0c e8 96 f9 ff ff 44 8b 54 24 0c 44 89 e2 48 89 ee 41 89 c0 bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 89 44 24 0c e8 c8 f9 ff ff 8b 44
RSP: 002b:00007f4e95582f30 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 0000000000419544
RDX: 0000000000010000 RSI: 0000000020000100 RDI: 00000000ffffff9c
RBP: 0000000020000100 R08: 0000000000000000 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000010000
R13: 0000000020000100 R14: 00007f4e95583000 R15: 0000000020061000

Allocated by task 11299:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:427 [inline]
 ____kasan_kmalloc+0xc2/0xf0 mm/kasan/common.c:506
 kasan_kmalloc include/linux/kasan.h:233 [inline]
 kmem_cache_alloc_trace+0x21b/0x350 mm/slub.c:2934
 kmalloc include/linux/slab.h:554 [inline]
 kzalloc include/linux/slab.h:684 [inline]
 smk_fetch security/smack/smack_lsm.c:288 [inline]
 smack_d_instantiate+0x65c/0xcc0 security/smack/smack_lsm.c:3411
 security_d_instantiate+0xa5/0x100 security/security.c:1987
 d_instantiate+0x51/0x90 fs/dcache.c:2006
 shmem_symlink+0x53f/0x6f0 mm/shmem.c:3131
 vfs_symlink+0x3a0/0x540 fs/namei.c:4178
 do_symlinkat+0x1c9/0x440 fs/namei.c:4208
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff88802b424e00
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 152 bytes to the right of
 256-byte region [ffff88802b424e00, ffff88802b424f00)
The buggy address belongs to the page:
page:ffffea0000ad0900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2b424
head:ffffea0000ad0900 order:1 compound_mapcount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010841b40
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88802b424e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802b424f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802b424f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                            ^
 ffff88802b425000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802b425080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (3):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Title
ci-upstream-kasan-gce-smack-root	2021/04/14 01:33	upstream	eebe426d	a184b83e	.config	log	report	info	KASAN: slab-out-of-bounds Read in reiserfs_xattr_get
ci-upstream-kasan-gce-smack-root	2021/04/08 01:29	upstream	3a229812	6a81331a	.config	log	report	info	KASAN: slab-out-of-bounds Read in reiserfs_xattr_get
ci-upstream-kasan-gce-smack-root	2021/04/03 19:38	upstream	57fbdb15	6a81331a	.config	log	report	info	KASAN: slab-out-of-bounds Read in reiserfs_xattr_get