[syzbot] [xfs?] KASAN: slab-out-of-bounds Read in xlog_cksum

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 99fa936e8e4f Merge tag 'affs-6.14-rc5-tag' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=111c9464580000
kernel config: https://syzkaller.appspot.com/x/.config?x=2040405600e83619
dashboard link: https://syzkaller.appspot.com/bug?extid=9f6d080dece587cfdd4c
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=132f0078580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1483fc54580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-99fa936e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ef04f83d96f6/vmlinux-99fa936e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/583a7eea5c8e/bzImage-99fa936e.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/6232fcdbddfb/mount_1.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=11d457a0580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9f6d08...@syzkaller.appspotmail.com

=======================================================
XFS (loop0): Mounting V5 Filesystem bfdc47fc-10d8-4eed-a562-11a831b3f791
==================================================================
BUG: KASAN: slab-out-of-bounds in crc32c_le_arch+0xc7/0x1b0 arch/x86/lib/crc32-glue.c:81
Read of size 8 at addr ffff888040dfea00 by task syz-executor260/5304

CPU: 0 UID: 0 PID: 5304 Comm: syz-executor260 Not tainted 6.14.0-rc5-syzkaller-00013-g99fa936e8e4f #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0x16e/0x5b0 mm/kasan/report.c:521
kasan_report+0x143/0x180 mm/kasan/report.c:634
crc32c_le_arch+0xc7/0x1b0 arch/x86/lib/crc32-glue.c:81
__crc32c_le include/linux/crc32.h:36 [inline]
crc32c include/linux/crc32c.h:9 [inline]
xlog_cksum+0x91/0xf0 fs/xfs/xfs_log.c:1588
xlog_recover_process+0x78/0x1e0 fs/xfs/xfs_log_recover.c:2900
xlog_do_recovery_pass+0xa01/0xdc0 fs/xfs/xfs_log_recover.c:3235
xlog_verify_head+0x21f/0x5a0 fs/xfs/xfs_log_recover.c:1058
xlog_find_tail+0xa04/0xdf0 fs/xfs/xfs_log_recover.c:1315
xlog_recover+0xe1/0x540 fs/xfs/xfs_log_recover.c:3419
xfs_log_mount+0x252/0x3e0 fs/xfs/xfs_log.c:666
xfs_mountfs+0xfbb/0x2500 fs/xfs/xfs_mount.c:878
xfs_fs_fill_super+0x1223/0x1550 fs/xfs/xfs_super.c:1817
get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
vfs_get_tree+0x90/0x2b0 fs/super.c:1814
do_new_mount+0x2be/0xb40 fs/namespace.c:3560
do_mount fs/namespace.c:3900 [inline]
__do_sys_mount fs/namespace.c:4111 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff347850dfa
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 5e 04 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcece53ae8 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffcece53b00 RCX: 00007ff347850dfa
RDX: 0000400000000500 RSI: 0000400000000200 RDI: 00007ffcece53b00
RBP: 0000400000000500 R08: 00007ffcece53b40 R09: 002c6563726f666e
R10: 0000000002218a5d R11: 0000000000000202 R12: 0000400000000200
R13: 0000000000000005 R14: 0000000000000004 R15: 00007ffcece53b40
</TASK>

Allocated by task 5304:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4294 [inline]
__kmalloc_node_noprof+0x290/0x4d0 mm/slub.c:4300
__kvmalloc_node_noprof+0x72/0x190 mm/util.c:662
xlog_do_recovery_pass+0x143/0xdc0 fs/xfs/xfs_log_recover.c:3016
xlog_verify_head+0x21f/0x5a0 fs/xfs/xfs_log_recover.c:1058
xlog_find_tail+0xa04/0xdf0 fs/xfs/xfs_log_recover.c:1315
xlog_recover+0xe1/0x540 fs/xfs/xfs_log_recover.c:3419
xfs_log_mount+0x252/0x3e0 fs/xfs/xfs_log.c:666
xfs_mountfs+0xfbb/0x2500 fs/xfs/xfs_mount.c:878
xfs_fs_fill_super+0x1223/0x1550 fs/xfs/xfs_super.c:1817
get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
vfs_get_tree+0x90/0x2b0 fs/super.c:1814
do_new_mount+0x2be/0xb40 fs/namespace.c:3560
do_mount fs/namespace.c:3900 [inline]
__do_sys_mount fs/namespace.c:4111 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888040dfe800
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes to the right of
allocated 512-byte region [ffff888040dfe800, ffff888040dfea00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x40dfe
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801b041c80 ffffea0000d6ab00 dead000000000004
raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff88801b041c80 ffffea0000d6ab00 dead000000000004
head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 04fff00000000001 ffffea0001037f81 ffffffffffffffff 0000000000000000
head: 0000000000000002 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2, tgid 2 (kthreadd), ts 25533552797, free_ts 0
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
prep_new_page mm/page_alloc.c:1559 [inline]
get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
__alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739
alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
alloc_slab_page mm/slub.c:2423 [inline]
allocate_slab+0x8f/0x3a0 mm/slub.c:2587
new_slab mm/slub.c:2640 [inline]
___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
__slab_alloc+0x58/0xa0 mm/slub.c:3916
__slab_alloc_node mm/slub.c:3991 [inline]
slab_alloc_node mm/slub.c:4152 [inline]
__kmalloc_cache_noprof+0x27b/0x390 mm/slub.c:4320
kmalloc_noprof include/linux/slab.h:901 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
set_kthread_struct+0xc2/0x330 kernel/kthread.c:126
copy_process+0x1179/0x3cf0 kernel/fork.c:2331
kernel_clone+0x226/0x8e0 kernel/fork.c:2815
kernel_thread+0x1c0/0x250 kernel/fork.c:2877
create_kthread kernel/kthread.c:487 [inline]
kthreadd+0x60d/0x810 kernel/kthread.c:847
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page_owner free stack trace missing

Memory state around the buggy address:
ffff888040dfe900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888040dfe980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888040dfea00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff888040dfea80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888040dfeb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
This report is generated by a bot. It may contain errors.
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syzbot engineers can be reached at syzk...@googlegroups.com.

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If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
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If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[Edward Adam Davis]

#syz test

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index f8851ff835de..160eb6738c8c 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -1581,8 +1581,12 @@ xlog_cksum(
union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead;
int i;
int xheads;
+ int tail_xhead_len;

xheads = DIV_ROUND_UP(size, XLOG_HEADER_CYCLE_SIZE);
+ tail_xhead_len = size % XLOG_HEADER_CYCLE_SIZE;
+ if (sizeof(struct xlog_rec_ext_header) > tail_xhead_len)
+ xheads -= 1;

for (i = 1; i < xheads; i++) {
crc = crc32c(crc, &xhdr[i].hic_xheader,

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-out-of-bounds Read in xlog_cksum

=======================================================
XFS (loop0): Mounting V5 Filesystem bfdc47fc-10d8-4eed-a562-11a831b3f791
==================================================================
BUG: KASAN: slab-out-of-bounds in crc32c_le_arch+0xc7/0x1b0 arch/x86/lib/crc32-glue.c:81

Read of size 8 at addr ffff888032f85200 by task syz.0.16/5864

CPU: 0 UID: 0 PID: 5864 Comm: syz.0.16 Not tainted 6.14.0-rc5-syzkaller-g48a5eed9ad58-dirty #0

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0x16e/0x5b0 mm/kasan/report.c:521
kasan_report+0x143/0x180 mm/kasan/report.c:634
crc32c_le_arch+0xc7/0x1b0 arch/x86/lib/crc32-glue.c:81
__crc32c_le include/linux/crc32.h:36 [inline]
crc32c include/linux/crc32c.h:9 [inline]

xlog_cksum+0xcf/0x130 fs/xfs/xfs_log.c:1592

xlog_recover_process+0x78/0x1e0 fs/xfs/xfs_log_recover.c:2900
xlog_do_recovery_pass+0xa01/0xdc0 fs/xfs/xfs_log_recover.c:3235
xlog_verify_head+0x21f/0x5a0 fs/xfs/xfs_log_recover.c:1058
xlog_find_tail+0xa04/0xdf0 fs/xfs/xfs_log_recover.c:1315
xlog_recover+0xe1/0x540 fs/xfs/xfs_log_recover.c:3419
xfs_log_mount+0x252/0x3e0 fs/xfs/xfs_log.c:666
xfs_mountfs+0xfbb/0x2500 fs/xfs/xfs_mount.c:878
xfs_fs_fill_super+0x1223/0x1550 fs/xfs/xfs_super.c:1817
get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
vfs_get_tree+0x90/0x2b0 fs/super.c:1814
do_new_mount+0x2be/0xb40 fs/namespace.c:3560
do_mount fs/namespace.c:3900 [inline]
__do_sys_mount fs/namespace.c:4111 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

RIP: 0033:0x7f2098f8e90a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f2099e4fe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f2099e4fef0 RCX: 00007f2098f8e90a
RDX: 0000400000000500 RSI: 0000400000000200 RDI: 00007f2099e4feb0
RBP: 0000400000000500 R08: 00007f2099e4fef0 R09: 0000000002218a5d
R10: 0000000002218a5d R11: 0000000000000246 R12: 0000400000000200
R13: 00007f2099e4feb0 R14: 0000000000009706 R15: 0000400000000100
</TASK>

Allocated by task 5864:

kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4294 [inline]
__kmalloc_node_noprof+0x290/0x4d0 mm/slub.c:4300
__kvmalloc_node_noprof+0x72/0x190 mm/util.c:662
xlog_do_recovery_pass+0x143/0xdc0 fs/xfs/xfs_log_recover.c:3016
xlog_verify_head+0x21f/0x5a0 fs/xfs/xfs_log_recover.c:1058
xlog_find_tail+0xa04/0xdf0 fs/xfs/xfs_log_recover.c:1315
xlog_recover+0xe1/0x540 fs/xfs/xfs_log_recover.c:3419
xfs_log_mount+0x252/0x3e0 fs/xfs/xfs_log.c:666
xfs_mountfs+0xfbb/0x2500 fs/xfs/xfs_mount.c:878
xfs_fs_fill_super+0x1223/0x1550 fs/xfs/xfs_super.c:1817
get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
vfs_get_tree+0x90/0x2b0 fs/super.c:1814
do_new_mount+0x2be/0xb40 fs/namespace.c:3560
do_mount fs/namespace.c:3900 [inline]
__do_sys_mount fs/namespace.c:4111 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888032f85000

which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes to the right of

allocated 512-byte region [ffff888032f85000, ffff888032f85200)

The buggy address belongs to the physical page:

page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x32f84

head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0

anon flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801b041c80 0000000000000000 dead000000000001

raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000

head: 04fff00000000040 ffff88801b041c80 0000000000000000 dead000000000001

head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000

head: 04fff00000000001 ffffea0000cbe101 ffffffffffffffff 0000000000000000
head: ffff888000000002 0000000000000000 00000000ffffffff 0000000000000000

page dumped because: kasan: bad access detected
page_owner tracks the page as allocated

page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5658, tgid 5658 (syz-executor), ts 131552625607, free_ts 131548944772

set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
prep_new_page mm/page_alloc.c:1559 [inline]
get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
__alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739
alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
alloc_slab_page mm/slub.c:2423 [inline]
allocate_slab+0x8f/0x3a0 mm/slub.c:2587
new_slab mm/slub.c:2640 [inline]
___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
__slab_alloc+0x58/0xa0 mm/slub.c:3916
__slab_alloc_node mm/slub.c:3991 [inline]
slab_alloc_node mm/slub.c:4152 [inline]

__do_kmalloc_node mm/slub.c:4293 [inline]
__kmalloc_noprof+0x2e6/0x4c0 mm/slub.c:4306
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
fib6_info_alloc+0x2e/0xf0 net/ipv6/ip6_fib.c:155
ip6_route_info_create+0x445/0x12b0 net/ipv6/route.c:3766
addrconf_f6i_alloc+0x3c2/0x7f0 net/ipv6/route.c:4593
ipv6_add_addr+0x5b6/0x1090 net/ipv6/addrconf.c:1119
inet6_addr_add+0x3ae/0xe30 net/ipv6/addrconf.c:3047
inet6_rtm_newaddr+0xa89/0xf10 net/ipv6/addrconf.c:5054
rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6912
netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2533
page last free pid 5678 tgid 5678 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1127 [inline]
free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660
mm_free_pgd kernel/fork.c:815 [inline]
__mmdrop+0xb9/0x3d0 kernel/fork.c:931
exec_mmap+0x7a5/0x890 fs/exec.c:1011
begin_new_exec+0x1281/0x2100 fs/exec.c:1267
load_elf_binary+0x973/0x2820 fs/binfmt_elf.c:1002
search_binary_handler fs/exec.c:1775 [inline]
exec_binprm fs/exec.c:1807 [inline]
bprm_execve+0x979/0x1430 fs/exec.c:1859
do_execveat_common+0x57f/0x710 fs/exec.c:1966
do_execve fs/exec.c:2040 [inline]
__do_sys_execve fs/exec.c:2116 [inline]
__se_sys_execve fs/exec.c:2111 [inline]
__x64_sys_execve+0x92/0xb0 fs/exec.c:2111

do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:

ffff888032f85100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888032f85180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888032f85200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff888032f85280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888032f85300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


Tested on:

commit: 48a5eed9 Merge tag 'devicetree-fixes-for-6.14-2' of gi..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15c10254580000

kernel config: https://syzkaller.appspot.com/x/.config?x=2040405600e83619
dashboard link: https://syzkaller.appspot.com/bug?extid=9f6d080dece587cfdd4c
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=10ebd8b7980000

[Eric Biggers]

This got sent "To:" me because of crc32c in the call stack. The bug is in XFS,
though; it's passing an invalid buffer to crc32c().

- Eric

[Edward Adam Davis]

#syz test

diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c

index f8851ff835de..6b7eee3c9f7f 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -1583,6 +1583,7 @@ xlog_cksum(
int xheads;

xheads = DIV_ROUND_UP(size, XLOG_HEADER_CYCLE_SIZE);
+ printk("xheads: %d, size: %d, %s\n", xheads, size, __func__);

for (i = 1; i < xheads; i++) {
crc = crc32c(crc, &xhdr[i].hic_xheader,

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index b3c27dbccce8..257abbe9c3fa 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -2969,6 +2969,7 @@ xlog_valid_rec_header(
* and h_len must not be greater than LR buffer size.
*/
hlen = be32_to_cpu(rhead->h_len);
+ printk("hlen: %d, bufsize: %d, %s\n", hlen, bufsize, __func__);
if (XFS_IS_CORRUPT(log->l_mp, hlen <= 0 || hlen > bufsize))
return -EFSCORRUPTED;

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-out-of-bounds Read in xlog_cksum

hlen: 64512, bufsize: 65536, xlog_valid_rec_header
hlen: 64512, bufsize: 65536, xlog_valid_rec_header
xheads: 2, size: 64512, xlog_cksum

==================================================================
BUG: KASAN: slab-out-of-bounds in crc32c_le_arch+0xc7/0x1b0 arch/x86/lib/crc32-glue.c:81

Read of size 8 at addr ffff88804899fa00 by task syz.0.16/5851

CPU: 0 UID: 0 PID: 5851 Comm: syz.0.16 Not tainted 6.14.0-rc5-syzkaller-g48a5eed9ad58-dirty #0

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0x16e/0x5b0 mm/kasan/report.c:521
kasan_report+0x143/0x180 mm/kasan/report.c:634
crc32c_le_arch+0xc7/0x1b0 arch/x86/lib/crc32-glue.c:81
__crc32c_le include/linux/crc32.h:36 [inline]
crc32c include/linux/crc32c.h:9 [inline]

xlog_cksum+0xcb/0x130 fs/xfs/xfs_log.c:1589
xlog_recover_process+0x78/0x1e0 fs/xfs/xfs_log_recover.c:2900
xlog_do_recovery_pass+0xa01/0xdc0 fs/xfs/xfs_log_recover.c:3236

xlog_verify_head+0x21f/0x5a0 fs/xfs/xfs_log_recover.c:1058
xlog_find_tail+0xa04/0xdf0 fs/xfs/xfs_log_recover.c:1315

xlog_recover+0xe1/0x540 fs/xfs/xfs_log_recover.c:3420

xfs_log_mount+0x252/0x3e0 fs/xfs/xfs_log.c:666
xfs_mountfs+0xfbb/0x2500 fs/xfs/xfs_mount.c:878
xfs_fs_fill_super+0x1223/0x1550 fs/xfs/xfs_super.c:1817
get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
vfs_get_tree+0x90/0x2b0 fs/super.c:1814
do_new_mount+0x2be/0xb40 fs/namespace.c:3560
do_mount fs/namespace.c:3900 [inline]
__do_sys_mount fs/namespace.c:4111 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

RIP: 0033:0x7f5c0bb8e90a

Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f5c0ca1fe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f5c0ca1fef0 RCX: 00007f5c0bb8e90a
RDX: 0000400000000500 RSI: 0000400000000200 RDI: 00007f5c0ca1feb0
RBP: 0000400000000500 R08: 00007f5c0ca1fef0 R09: 0000000002218a5d

R10: 0000000002218a5d R11: 0000000000000246 R12: 0000400000000200

R13: 00007f5c0ca1feb0 R14: 0000000000009706 R15: 0000400000000100
</TASK>

Allocated by task 5851:

kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4294 [inline]
__kmalloc_node_noprof+0x290/0x4d0 mm/slub.c:4300
__kvmalloc_node_noprof+0x72/0x190 mm/util.c:662

xlog_do_recovery_pass+0x143/0xdc0 fs/xfs/xfs_log_recover.c:3017

xlog_verify_head+0x21f/0x5a0 fs/xfs/xfs_log_recover.c:1058
xlog_find_tail+0xa04/0xdf0 fs/xfs/xfs_log_recover.c:1315

xlog_recover+0xe1/0x540 fs/xfs/xfs_log_recover.c:3420

xfs_log_mount+0x252/0x3e0 fs/xfs/xfs_log.c:666
xfs_mountfs+0xfbb/0x2500 fs/xfs/xfs_mount.c:878
xfs_fs_fill_super+0x1223/0x1550 fs/xfs/xfs_super.c:1817
get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
vfs_get_tree+0x90/0x2b0 fs/super.c:1814
do_new_mount+0x2be/0xb40 fs/namespace.c:3560
do_mount fs/namespace.c:3900 [inline]
__do_sys_mount fs/namespace.c:4111 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88804899f800

which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes to the right of

allocated 512-byte region [ffff88804899f800, ffff88804899fa00)

The buggy address belongs to the physical page:

page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4899e

head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801b041c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff88801b041c80 0000000000000000 dead000000000001
head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000

head: 04fff00000000001 ffffea0001226781 ffffffffffffffff 0000000000000000
head: 0000000700000002 0000000000000000 00000000ffffffff 0000000000000000

page dumped because: kasan: bad access detected
page_owner tracks the page as allocated

page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5614, tgid 5614 (syz-executor), ts 129766503794, free_ts 128754914187

set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
prep_new_page mm/page_alloc.c:1559 [inline]
get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477
__alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739
alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
alloc_slab_page mm/slub.c:2423 [inline]
allocate_slab+0x8f/0x3a0 mm/slub.c:2587
new_slab mm/slub.c:2640 [inline]
___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
__slab_alloc+0x58/0xa0 mm/slub.c:3916
__slab_alloc_node mm/slub.c:3991 [inline]
slab_alloc_node mm/slub.c:4152 [inline]
__do_kmalloc_node mm/slub.c:4293 [inline]
__kmalloc_noprof+0x2e6/0x4c0 mm/slub.c:4306
kmalloc_noprof include/linux/slab.h:905 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]

ops_init+0x76/0x5b0 net/core/net_namespace.c:128
setup_net+0x287/0x9e0 net/core/net_namespace.c:362
copy_net_ns+0x33f/0x570 net/core/net_namespace.c:516
create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228
ksys_unshare+0x57d/0xa70 kernel/fork.c:3342
__do_sys_unshare kernel/fork.c:3413 [inline]
__se_sys_unshare kernel/fork.c:3411 [inline]
__x64_sys_unshare+0x38/0x40 kernel/fork.c:3411

do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83

page last free pid 5603 tgid 5603 stack trace:

reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1127 [inline]

free_unref_folios+0xe40/0x18b0 mm/page_alloc.c:2707
folios_put_refs+0x76c/0x860 mm/swap.c:994
free_pages_and_swap_cache+0x2e5/0x690 mm/swap_state.c:331
__tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline]
tlb_batch_pages_flush mm/mmu_gather.c:149 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:389 [inline]
tlb_flush_mmu+0x3a3/0x680 mm/mmu_gather.c:396
tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:488
vms_clear_ptes+0x432/0x530 mm/vma.c:1144
vms_complete_munmap_vmas+0x210/0x8f0 mm/vma.c:1186
do_vmi_align_munmap+0x5ef/0x6f0 mm/vma.c:1445
do_vmi_munmap+0x24e/0x2d0 mm/vma.c:1493
__vm_munmap+0x372/0x510 mm/vma.c:2951
__do_sys_munmap mm/mmap.c:1084 [inline]
__se_sys_munmap mm/mmap.c:1081 [inline]
__x64_sys_munmap+0x60/0x70 mm/mmap.c:1081

do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:

ffff88804899f900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88804899f980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88804899fa00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff88804899fa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88804899fb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

==================================================================


Tested on:

commit: 48a5eed9 Merge tag 'devicetree-fixes-for-6.14-2' of gi..

git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12d2fc64580000

kernel config: https://syzkaller.appspot.com/x/.config?x=2040405600e83619
dashboard link: https://syzkaller.appspot.com/bug?extid=9f6d080dece587cfdd4c
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=10f938b7980000

[Julian Sun]

#syz test: linux-next

[syzbot]

> #syz test: linux-next

want either no args or 2 args (repo, branch), got 6

[Julian Sun]

#syz test

On 3/5/25 00:15, syzbot wrote:

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-out-of-bounds Read in xlog_cksum

=======================================================
XFS (loop0): Mounting V5 Filesystem bfdc47fc-10d8-4eed-a562-11a831b3f791
==================================================================
BUG: KASAN: slab-out-of-bounds in crc32c_le_arch+0xc7/0x1b0 arch/x86/lib/crc32-glue.c:81

Read of size 8 at addr ffff888040eb5200 by task syz.0.16/5913

CPU: 0 UID: 0 PID: 5913 Comm: syz.0.16 Not tainted 6.14.0-rc6-syzkaller-gb7f94fcf5546 #0

RIP: 0033:0x7f010618e90a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f0106f3ce68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f0106f3cef0 RCX: 00007f010618e90a
RDX: 0000400000000500 RSI: 0000400000000200 RDI: 00007f0106f3ceb0
RBP: 0000400000000500 R08: 00007f0106f3cef0 R09: 0000000002218a5d

R10: 0000000002218a5d R11: 0000000000000246 R12: 0000400000000200

R13: 00007f0106f3ceb0 R14: 0000000000009706 R15: 0000400000000100
</TASK>

Allocated by task 5913:

kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
__kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4294 [inline]
__kmalloc_node_noprof+0x290/0x4d0 mm/slub.c:4300
__kvmalloc_node_noprof+0x72/0x190 mm/util.c:662
xlog_do_recovery_pass+0x143/0xdc0 fs/xfs/xfs_log_recover.c:3016
xlog_verify_head+0x21f/0x5a0 fs/xfs/xfs_log_recover.c:1058
xlog_find_tail+0xa04/0xdf0 fs/xfs/xfs_log_recover.c:1315
xlog_recover+0xe1/0x540 fs/xfs/xfs_log_recover.c:3419
xfs_log_mount+0x252/0x3e0 fs/xfs/xfs_log.c:666
xfs_mountfs+0xfbb/0x2500 fs/xfs/xfs_mount.c:878
xfs_fs_fill_super+0x1223/0x1550 fs/xfs/xfs_super.c:1817
get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
vfs_get_tree+0x90/0x2b0 fs/super.c:1814
do_new_mount+0x2be/0xb40 fs/namespace.c:3560
do_mount fs/namespace.c:3900 [inline]
__do_sys_mount fs/namespace.c:4111 [inline]
__se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4088
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888040eb5000

which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes to the right of

allocated 512-byte region [ffff888040eb5000, ffff888040eb5200)

The buggy address belongs to the physical page:

page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x40eb4

head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0

ksm flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801b041c80 ffffea0000d00580 dead000000000003

raw: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000

head: 04fff00000000040 ffff88801b041c80 ffffea0000d00580 dead000000000003

head: 0000000000000000 0000000080080008 00000000f5000000 0000000000000000

head: 04fff00000000001 ffffea000103ad01 ffffffffffffffff 0000000000000000

head: 0000000000000002 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated

page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 2, tgid 2 (kthreadd), ts 23865404352, free_ts 0

set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551
prep_new_page mm/page_alloc.c:1559 [inline]
get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477

__alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4740

alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270
alloc_slab_page mm/slub.c:2423 [inline]
allocate_slab+0x8f/0x3a0 mm/slub.c:2587
new_slab mm/slub.c:2640 [inline]
___slab_alloc+0xc27/0x14a0 mm/slub.c:3826
__slab_alloc+0x58/0xa0 mm/slub.c:3916
__slab_alloc_node mm/slub.c:3991 [inline]
slab_alloc_node mm/slub.c:4152 [inline]
__kmalloc_cache_noprof+0x27b/0x390 mm/slub.c:4320
kmalloc_noprof include/linux/slab.h:901 [inline]
kzalloc_noprof include/linux/slab.h:1037 [inline]
set_kthread_struct+0xc2/0x330 kernel/kthread.c:126
copy_process+0x1179/0x3cf0 kernel/fork.c:2331
kernel_clone+0x226/0x8e0 kernel/fork.c:2815
kernel_thread+0x1c0/0x250 kernel/fork.c:2877
create_kthread kernel/kthread.c:487 [inline]
kthreadd+0x60d/0x810 kernel/kthread.c:847
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
page_owner free stack trace missing

Memory state around the buggy address:

ffff888040eb5100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888040eb5180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888040eb5200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff888040eb5280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888040eb5300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


Tested on:

commit: b7f94fcf Merge tag 'sched_ext-for-6.14-rc6-fixes' of g..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16f4cc78580000
kernel config: https://syzkaller.appspot.com/x/.config?x=31c94a07ddad0b00

dashboard link: https://syzkaller.appspot.com/bug?extid=9f6d080dece587cfdd4c
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Note: no patches were applied.