[syzbot] [jfs?] general protection fault in jfs_error (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2d5404caa8c7 Linux 6.12-rc7
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1772fe30580000
kernel config: https://syzkaller.appspot.com/x/.config?x=d2aeec8c0b2e420c
dashboard link: https://syzkaller.appspot.com/bug?extid=5f0d7af0e45fae10edd1
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=17b2f4e8580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=119f7ea7980000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-2d5404ca.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c68277f7b0f1/vmlinux-2d5404ca.xz
kernel image: https://storage.googleapis.com/syzbot-assets/161b075483b1/bzImage-2d5404ca.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/6b6a26f0435b/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5f0d7a...@syzkaller.appspotmail.com

ERROR: (device loop0): remounting filesystem as read-only
ERROR: (device loop0): dbFindCtl: Corrupt dmapctl page
jfs_create: dtInsert returned -EIO
ERROR: (device (efault)): jfs_create:
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000a: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000050-0x0000000000000057]
CPU: 0 UID: 0 PID: 5313 Comm: syz-executor116 Not tainted 6.12.0-rc7-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:sb_rdonly include/linux/fs.h:2292 [inline]
RIP: 0010:jfs_handle_error fs/jfs/super.c:66 [inline]
RIP: 0010:jfs_error+0x159/0x2e0 fs/jfs/super.c:98
Code: 08 48 c7 c7 40 e9 42 8c 48 89 74 24 08 4c 89 f9 e8 4c 22 9c 08 4d 8d 65 50 4d 89 e7 49 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <41> 80 3c 07 00 74 08 4c 89 e7 e8 48 5e d6 fe 49 8b 1c 24 48 89 de
RSP: 0018:ffffc9000ce4fa20 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 1c32466592978100
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc9000ce4fb30 R08: ffffffff8174a13c R09: 1ffff11003f8519a
R10: dffffc0000000000 R11: ffffed1003f8519b R12: 0000000000000050
R13: 0000000000000000 R14: 1ffff920019c9f4c R15: 000000000000000a
FS: 0000555595511380(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055fdcfd20000 CR3: 0000000043170000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
jfs_create+0x81d/0xbb0 fs/jfs/namei.c:140
vfs_create+0x23c/0x3d0 fs/namei.c:3294
do_mknodat+0x447/0x5b0 fs/namei.c:4185
__do_sys_mknod fs/namei.c:4218 [inline]
__se_sys_mknod fs/namei.c:4216 [inline]
__x64_sys_mknod+0x8c/0xa0 fs/namei.c:4216
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: 0033:0x7f17ac91d9f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff56943258 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007fff56943428 RCX: 00007f17ac91d9f9
RDX: 0000000000000701 RSI: 0000000000000000 RDI: 0000000020000000
RBP: 00007f17ac996610 R08: 0000000020000000 R09: 00007fff56943428
R10: 00007fff56943120 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff56943418 R14: 0000000000000001 R15: 0000000000000001
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:sb_rdonly include/linux/fs.h:2292 [inline]
RIP: 0010:jfs_handle_error fs/jfs/super.c:66 [inline]
RIP: 0010:jfs_error+0x159/0x2e0 fs/jfs/super.c:98
Code: 08 48 c7 c7 40 e9 42 8c 48 89 74 24 08 4c 89 f9 e8 4c 22 9c 08 4d 8d 65 50 4d 89 e7 49 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <41> 80 3c 07 00 74 08 4c 89 e7 e8 48 5e d6 fe 49 8b 1c 24 48 89 de
RSP: 0018:ffffc9000ce4fa20 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: dffffc0000000000 RCX: 1c32466592978100
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: ffffc9000ce4fb30 R08: ffffffff8174a13c R09: 1ffff11003f8519a
R10: dffffc0000000000 R11: ffffed1003f8519b R12: 0000000000000050
R13: 0000000000000000 R14: 1ffff920019c9f4c R15: 000000000000000a
FS: 0000555595511380(0000) GS:ffff88801fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055fdcfd20000 CR3: 0000000043170000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 08 48 c7 or %cl,-0x39(%rax)
3: c7 40 e9 42 8c 48 89 movl $0x89488c42,-0x17(%rax)
a: 74 24 je 0x30
c: 08 4c 89 f9 or %cl,-0x7(%rcx,%rcx,4)
10: e8 4c 22 9c 08 call 0x89c2261
15: 4d 8d 65 50 lea 0x50(%r13),%r12
19: 4d 89 e7 mov %r12,%r15
1c: 49 c1 ef 03 shr $0x3,%r15
20: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
27: fc ff df
* 2a: 41 80 3c 07 00 cmpb $0x0,(%r15,%rax,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 e7 mov %r12,%rdi
34: e8 48 5e d6 fe call 0xfed65e81
39: 49 8b 1c 24 mov (%r12),%rbx
3d: 48 89 de mov %rbx,%rsi


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

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:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

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

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-...@vger.kernel.org, syzkall...@googlegroups.com.

***

Subject: Re: general protection fault in jfs_error()
Author: dman...@yandex.ru

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git adc218676eef25575469234709c2d87185ca223a

diff --git a/fs/jfs/namei.c b/fs/jfs/namei.c
index d68a4e6ac345..d2eff3375aad 100644
--- a/fs/jfs/namei.c
+++ b/fs/jfs/namei.c
@@ -96,24 +96,29 @@ static int jfs_create(struct mnt_idmap *idmap, struct inode *dip,
}

tid = txBegin(dip->i_sb, 0);
+ /* Do not go further if jfs_handle_error() marks us read-only. */
+ if (unlikely(dip->i_sb->s_flags & SB_RDONLY)) {
+ rc = -EROFS;
+ goto out3;
+ }

mutex_lock_nested(&JFS_IP(dip)->commit_mutex, COMMIT_MUTEX_PARENT);
mutex_lock_nested(&JFS_IP(ip)->commit_mutex, COMMIT_MUTEX_CHILD);

rc = jfs_init_acl(tid, ip, dip);
if (rc)
- goto out3;
+ goto out4;

rc = jfs_init_security(tid, ip, dip, &dentry->d_name);
if (rc) {
txAbort(tid, 0);
- goto out3;
+ goto out4;
}

if ((rc = dtSearch(dip, &dname, &ino, &btstack, JFS_CREATE))) {
jfs_err("jfs_create: dtSearch returned %d", rc);
txAbort(tid, 0);
- goto out3;
+ goto out4;
}

tblk = tid_to_tblock(tid);
@@ -140,7 +145,7 @@ static int jfs_create(struct mnt_idmap *idmap, struct inode *dip,
txAbort(tid, 1); /* Marks Filesystem dirty */
} else
txAbort(tid, 0); /* Filesystem full */
- goto out3;
+ goto out4;
}

ip->i_op = &jfs_file_inode_operations;
@@ -155,10 +160,12 @@ static int jfs_create(struct mnt_idmap *idmap, struct inode *dip,

rc = txCommit(tid, 2, &iplist[0], 0);

- out3:
+ out4:
txEnd(tid);
mutex_unlock(&JFS_IP(ip)->commit_mutex);
mutex_unlock(&JFS_IP(dip)->commit_mutex);
+
+ out3:
if (rc) {
free_ea_wmap(ip);
clear_nlink(ip);

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+5f0d7a...@syzkaller.appspotmail.com
Tested-by: syzbot+5f0d7a...@syzkaller.appspotmail.com

Tested on:

commit: adc21867 Linux 6.12
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=1140b378580000
kernel config: https://syzkaller.appspot.com/x/.config?x=e31661728c1a4027

dashboard link: https://syzkaller.appspot.com/bug?extid=5f0d7af0e45fae10edd1
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=175f3378580000

Note: testing is done by a robot and is best-effort only.

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-...@vger.kernel.org, syzkall...@googlegroups.com.

***

Subject: Re: general protection fault in jfs_error()
Author: dman...@yandex.ru

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 158f238aa69d91ad74e535c73f552bd4b025109c

diff --git a/fs/jfs/jfs_mount.c b/fs/jfs/jfs_mount.c
index 98f9a432c336..c0a51defc5b7 100644
--- a/fs/jfs/jfs_mount.c
+++ b/fs/jfs/jfs_mount.c
@@ -303,12 +303,6 @@ static int chkSuper(struct super_block *sb)
/*
* validate superblock
*/
- /* validate fs signature */
- if (strncmp(j_sb->s_magic, JFS_MAGIC, 4) ||
- le32_to_cpu(j_sb->s_version) > JFS_VERSION) {
- rc = -EINVAL;
- goto out;
- }

bsize = le32_to_cpu(j_sb->s_bsize);
if (bsize != PSIZE) {
@@ -449,6 +443,18 @@ int updateSuper(struct super_block *sb, uint state)
return 0;
}

+static int validateSuper(struct buffer_head *bh)
+{
+ struct jfs_superblock *j_sb;
+
+ if (!bh)
+ return -EIO;
+
+ j_sb = (struct jfs_superblock *)bh->b_data;
+
+ return (strncmp(j_sb->s_magic, JFS_MAGIC, 4) == 0 &&
+ le32_to_cpu(j_sb->s_version) <= JFS_VERSION) ? 0 : -EINVAL;
+}

/*
* readSuper()
@@ -457,17 +463,17 @@ int updateSuper(struct super_block *sb, uint state)
*/
int readSuper(struct super_block *sb, struct buffer_head **bpp)
{
- /* read in primary superblock */
+ /* read in and validate primary superblock */
*bpp = sb_bread(sb, SUPER1_OFF >> sb->s_blocksize_bits);
- if (*bpp)
+ if (!validateSuper(*bpp))
return 0;

- /* read in secondary/replicated superblock */
+ /* read in and validate secondary/replicated superblock */
*bpp = sb_bread(sb, SUPER2_OFF >> sb->s_blocksize_bits);
- if (*bpp)
+ if (!validateSuper(*bpp))
return 0;

- return -EIO;
+ return -EINVAL;
}


diff --git a/fs/jfs/jfs_umount.c b/fs/jfs/jfs_umount.c
index 8ec43f53f686..5f01f767bc0a 100644
--- a/fs/jfs/jfs_umount.c
+++ b/fs/jfs/jfs_umount.c
@@ -104,14 +104,15 @@ int jfs_umount(struct super_block *sb)
* list (to signify skip logredo()).
*/
if (log) { /* log = NULL if read-only mount */
- updateSuper(sb, FM_CLEAN);
-
- /*
- * close log:
- *
- * remove file system from log active file system list.
- */
- rc = lmLogClose(sb);
+ rc = updateSuper(sb, FM_CLEAN);
+ if (!rc) {
+ /*
+ * close log:
+ *
+ * remove file system from log active file system list.
+ */
+ rc = lmLogClose(sb);
+ }
}
jfs_info("UnMount JFS Complete: rc = %d", rc);
return rc;
@@ -122,6 +123,7 @@ int jfs_umount_rw(struct super_block *sb)
{
struct jfs_sb_info *sbi = JFS_SBI(sb);
struct jfs_log *log = sbi->log;
+ int rc;

if (!log)
return 0;
@@ -147,7 +149,7 @@ int jfs_umount_rw(struct super_block *sb)
*/
filemap_write_and_wait(sbi->direct_inode->i_mapping);

- updateSuper(sb, FM_CLEAN);
+ rc = updateSuper(sb, FM_CLEAN);

- return lmLogClose(sb);
+ return rc ? rc : lmLogClose(sb);
}

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by: syzbot+5f0d7a...@syzkaller.appspotmail.com
Tested-by: syzbot+5f0d7a...@syzkaller.appspotmail.com

Tested on:

commit: 158f238a Merge tag 'for-linus-6.13-rc1-tag' of git://g..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=14f02930580000
kernel config: https://syzkaller.appspot.com/x/.config?x=6e547da255e4eefa

dashboard link: https://syzkaller.appspot.com/bug?extid=5f0d7af0e45fae10edd1
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=1087f2e8580000