[syzbot] [jfs?] general protection fault in inode_set_ctime_current

[syzbot] [jfs?] general protection fault in inode_set_ctime_current

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    6fab32bb6508 MAINTAINERS: add Mark Brown as a linux-next m..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16bd2d2f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=df98b4d1d5944c56
dashboard link: https://syzkaller.appspot.com/bug?extid=cd7590567cc388f064f3
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=155a8be2580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15078258580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-6fab32bb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b126dd4d891b/vmlinux-6fab32bb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ae26100863fd/bzImage-6fab32bb.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/6617e28639c8/mount_0.gz
  fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=125f8c92580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cd7590567cc388f064f3@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 32768
Oops: general protection fault, probably for non-canonical address 0xe00e9c0e000c60d6: 0000 [#1] SMP KASAN NOPTI
KASAN: maybe wild-memory-access in range [0x00750070006306b0-0x00750070006306b7]
CPU: 0 UID: 0 PID: 5495 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:timestamp_truncate fs/inode.c:2732 [inline]
RIP: 0010:inode_set_ctime_current+0xcf/0xb40 fs/inode.c:2774
Code: d8 48 c1 e8 03 48 89 44 24 30 42 80 3c 20 00 74 08 48 89 df e8 e2 67 e7 ff 4c 8b 3b 49 8d bf 40 06 00 00 48 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 d6 07 00 00 48 89 5c 24 20 41 8b 87 40
RSP: 0018:ffffc90002b4f600 EFLAGS: 00010202
RAX: 000ea00e000c60d6 RBX: ffff88801c1ab220 RCX: ffff8880002b0000
RDX: 0000000000000000 RSI: 187182c674eb3579 RDI: 00750070006306b2
RBP: ffffc90002b4f6f0 R08: ffffffff8f7cf377 R09: 1ffffffff1ef9e6e
R10: dffffc0000000000 R11: fffffbfff1ef9e6f R12: dffffc0000000000
R13: ffff88801c1abe60 R14: ffffc90002b4f660 R15: 0075007000630072
FS:  000055557920a500(0000) GS:ffff88808d733000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31463fff CR3: 0000000011599000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 jfs_create+0x7f7/0xa80 fs/jfs/namei.c:152
 lookup_open fs/namei.c:3796 [inline]
 open_last_lookups fs/namei.c:3895 [inline]
 path_openat+0x14f4/0x3830 fs/namei.c:4131
 do_filp_open+0x1fa/0x410 fs/namei.c:4161
 do_sys_openat2+0x121/0x1c0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1463
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3f1c98efc9
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:00007ffd9e448248 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f3f1cbe5fa0 RCX: 00007f3f1c98efc9
RDX: 000000000000275a RSI: 0000200000000140 RDI: ffffffffffffff9c
RBP: 00007f3f1ca11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3f1cbe5fa0 R14: 00007f3f1cbe5fa0 R15: 0000000000000004
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:timestamp_truncate fs/inode.c:2732 [inline]
RIP: 0010:inode_set_ctime_current+0xcf/0xb40 fs/inode.c:2774
Code: d8 48 c1 e8 03 48 89 44 24 30 42 80 3c 20 00 74 08 48 89 df e8 e2 67 e7 ff 4c 8b 3b 49 8d bf 40 06 00 00 48 89 f8 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 d6 07 00 00 48 89 5c 24 20 41 8b 87 40
RSP: 0018:ffffc90002b4f600 EFLAGS: 00010202
RAX: 000ea00e000c60d6 RBX: ffff88801c1ab220 RCX: ffff8880002b0000
RDX: 0000000000000000 RSI: 187182c674eb3579 RDI: 00750070006306b2
RBP: ffffc90002b4f6f0 R08: ffffffff8f7cf377 R09: 1ffffffff1ef9e6e
R10: dffffc0000000000 R11: fffffbfff1ef9e6f R12: dffffc0000000000
R13: ffff88801c1abe60 R14: ffffc90002b4f660 R15: 0075007000630072
FS:  000055557920a500(0000) GS:ffff88808d733000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffabbbdc000 CR3: 0000000011599000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	d8 48 c1             	fmuls  -0x3f(%rax)
   3:	e8 03 48 89 44       	call   0x4489480b
   8:	24 30                	and    $0x30,%al
   a:	42 80 3c 20 00       	cmpb   $0x0,(%rax,%r12,1)
   f:	74 08                	je     0x19
  11:	48 89 df             	mov    %rbx,%rdi
  14:	e8 e2 67 e7 ff       	call   0xffe767fb
  19:	4c 8b 3b             	mov    (%rbx),%r15
  1c:	49 8d bf 40 06 00 00 	lea    0x640(%r15),%rdi
  23:	48 89 f8             	mov    %rdi,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 20       	movzbl (%rax,%r12,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 d6 07 00 00    	jne    0x80d
  37:	48 89 5c 24 20       	mov    %rbx,0x20(%rsp)
  3c:	41                   	rex.B
  3d:	8b                   	.byte 0x8b
  3e:	87                   	.byte 0x87
  3f:	40                   	rex


---
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 syzkaller@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

Forwarded:

[syzbot]

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

***

Subject: 
Author: jkoolstra@xs4all.nl

#syz test

diff --git a/fs/jfs/jfs_dtree.c b/fs/jfs/jfs_dtree.c
index 0ab83bb7bbdf..07dd01c79ca2 100644
--- a/fs/jfs/jfs_dtree.c
+++ b/fs/jfs/jfs_dtree.c
@@ -170,8 +170,8 @@ static void dtGetKey(dtpage_t * p, int i, struct component_name * key,
 static int ciGetLeafPrefixKey(dtpage_t * lp, int li, dtpage_t * rp,
 			      int ri, struct component_name * key, int flag);
 
-static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
-			  ddata_t * data, struct dt_lock **);
+static int dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
+			 ddata_t * data, struct dt_lock **);
 
 static void dtMoveEntry(dtpage_t * sp, int si, dtpage_t * dp,
 			struct dt_lock ** sdtlock, struct dt_lock ** ddtlock,
@@ -891,7 +891,8 @@ int dtInsert(tid_t tid, struct inode *ip,
 	lv->length = 1;
 	dtlck->index++;
 
-	dtInsertEntry(p, index, name, &data, &dtlck);
+	if (!(rc = dtInsertEntry(p, index, name, &data, &dtlck)))
+		return rc;
 
 	/* linelock stbl of non-root leaf page */
 	if (!(p->header.flag & BT_ROOT)) {
@@ -3627,7 +3628,7 @@ static void dtGetKey(dtpage_t * p, int i,	/* entry index */
  *
  * return: entry slot index
  */
-static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
+static int dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 			  ddata_t * data, struct dt_lock ** dtlock)
 {
 	struct dtslot *h, *t;
@@ -3649,6 +3650,10 @@ static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 
 	/* allocate a free slot */
 	hsi = fsi = p->header.freelist;
+	if (fsi >= p->header.maxslot) {
+		jfs_err("Encountered corrupted dtpage before insert");
+		return -EIO;
+	}
 	h = &p->slot[fsi];
 	p->header.freelist = h->next;
 	--p->header.freecnt;
@@ -3697,6 +3702,10 @@ static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 	while (klen) {
 		/* get free slot */
 		fsi = p->header.freelist;
+		if (fsi >= p->header.maxslot) {
+			jfs_err("Encountered corrupted dtpage before insert");
+			return -EIO;
+		}
 		t = &p->slot[fsi];
 		p->header.freelist = t->next;
 		--p->header.freecnt;
@@ -3774,6 +3783,8 @@ static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 
 	/* advance next available entry index of stbl */
 	++p->header.nextindex;
+
+	return 0;
 }

Forwarded:

[syzbot]

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

***

Subject: 
Author: jkoolstra@xs4all.nl

#syz test

---
 fs/jfs/jfs_dtree.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/fs/jfs/jfs_dtree.c b/fs/jfs/jfs_dtree.c
index 0ab83bb7bbdf..e919de01c42a 100644
--- a/fs/jfs/jfs_dtree.c
+++ b/fs/jfs/jfs_dtree.c
@@ -170,8 +170,8 @@ static void dtGetKey(dtpage_t * p, int i, struct component_name * key,
 static int ciGetLeafPrefixKey(dtpage_t * lp, int li, dtpage_t * rp,
 			      int ri, struct component_name * key, int flag);
 
-static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
-			  ddata_t * data, struct dt_lock **);
+static int dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
+			 ddata_t * data, struct dt_lock **);
 
 static void dtMoveEntry(dtpage_t * sp, int si, dtpage_t * dp,
 			struct dt_lock ** sdtlock, struct dt_lock ** ddtlock,
@@ -891,7 +891,8 @@ int dtInsert(tid_t tid, struct inode *ip,
 	lv->length = 1;
 	dtlck->index++;
 
-	dtInsertEntry(p, index, name, &data, &dtlck);
+	if (!(rc = dtInsertEntry(p, index, name, &data, &dtlck)))
+		return rc;
 
 	/* linelock stbl of non-root leaf page */
 	if (!(p->header.flag & BT_ROOT)) {
@@ -3625,9 +3626,10 @@ static void dtGetKey(dtpage_t * p, int i,	/* entry index */
  * function: allocate free slot(s) and
  *	     write a leaf/internal entry
  *
- * return: entry slot index
+ * * return: 0 - success;
+ *	   errno - failure;
  */
-static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
+static int dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 			  ddata_t * data, struct dt_lock ** dtlock)
 {
 	struct dtslot *h, *t;
@@ -3649,6 +3651,10 @@ static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 
 	/* allocate a free slot */
 	hsi = fsi = p->header.freelist;
+	if (fsi >= ((p->header.flag & BT_ROOT) ? DTROOTMAXSLOT : p->header.maxslot)) {
+		jfs_err("Encountered corrupted dtpage before insert");
+		return -EIO;
+	}
 	h = &p->slot[fsi];
 	p->header.freelist = h->next;
 	--p->header.freecnt;
@@ -3697,6 +3703,10 @@ static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 	while (klen) {
 		/* get free slot */
 		fsi = p->header.freelist;
+		if (fsi >= ((p->header.flag & BT_ROOT) ? DTROOTMAXSLOT : p->header.maxslot)) {
+			jfs_err("Encountered corrupted dtpage before insert");
+			return -EIO;
+		}
 		t = &p->slot[fsi];
 		p->header.freelist = t->next;
 		--p->header.freecnt;
@@ -3774,6 +3784,8 @@ static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 
 	/* advance next available entry index of stbl */
 	++p->header.nextindex;
+
+	return 0;
 }
 
 
-- 
2.51.1.dirty

Re: Forwarded:

[Al Viro]

On Tue, Oct 28, 2025 at 10:25:20AM -0700, syzbot wrote:
> For archival purposes, forwarding an incoming command email to
> linux-kernel@vger.kernel.org.

For fuck sake, either generate a more useful subject, or take
that to a separate list just for syzbot use.

Do you really intend to end up in a bunch of .procmailrc?

Forwarded:

[syzbot]

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

***

Subject: 
Author: jkoolstra@xs4all.nl

#syz test

---
 fs/jfs/jfs_dtree.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/fs/jfs/jfs_dtree.c b/fs/jfs/jfs_dtree.c
index 0ab83bb7bbdf..e919de01c42a 100644
--- a/fs/jfs/jfs_dtree.c
+++ b/fs/jfs/jfs_dtree.c
@@ -170,8 +170,8 @@ static void dtGetKey(dtpage_t * p, int i, struct component_name * key,
 static int ciGetLeafPrefixKey(dtpage_t * lp, int li, dtpage_t * rp,
 			      int ri, struct component_name * key, int flag);
 
-static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
-			  ddata_t * data, struct dt_lock **);
+static int dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
+			 ddata_t * data, struct dt_lock **);
 
 static void dtMoveEntry(dtpage_t * sp, int si, dtpage_t * dp,
 			struct dt_lock ** sdtlock, struct dt_lock ** ddtlock,
@@ -891,7 +891,8 @@ int dtInsert(tid_t tid, struct inode *ip,
 	lv->length = 1;
 	dtlck->index++;
 
-	dtInsertEntry(p, index, name, &data, &dtlck);
+	if (!(rc = dtInsertEntry(p, index, name, &data, &dtlck)))
+		return rc;
 
 	/* linelock stbl of non-root leaf page */
 	if (!(p->header.flag & BT_ROOT)) {
@@ -3625,9 +3626,10 @@ static void dtGetKey(dtpage_t * p, int i,	/* entry index */
  * function: allocate free slot(s) and
  *	     write a leaf/internal entry
  *
- * return: entry slot index
+ * * return: 0 - success;
+ *	   errno - failure;
  */
-static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
+static int dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 			  ddata_t * data, struct dt_lock ** dtlock)
 {
 	struct dtslot *h, *t;
@@ -3649,6 +3651,10 @@ static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 
 	/* allocate a free slot */
 	hsi = fsi = p->header.freelist;
+	if (fsi >= ((p->header.flag & BT_ROOT) ? DTROOTMAXSLOT : p->header.maxslot)) {
+		jfs_err("Encountered corrupted dtpage before insert");
+		return -EIO;
+	}
 	h = &p->slot[fsi];
 	p->header.freelist = h->next;
 	--p->header.freecnt;
@@ -3697,6 +3703,10 @@ static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 	while (klen) {
 		/* get free slot */
 		fsi = p->header.freelist;
+		if (fsi >= ((p->header.flag & BT_ROOT) ? DTROOTMAXSLOT : p->header.maxslot)) {
+			jfs_err("Encountered corrupted dtpage before insert");
+			return -EIO;
+		}
 		t = &p->slot[fsi];
 		p->header.freelist = t->next;
 		--p->header.freecnt;
@@ -3774,6 +3784,8 @@ static void dtInsertEntry(dtpage_t * p, int index, struct component_name * key,
 
 	/* advance next available entry index of stbl */
 	++p->header.nextindex;
+
+	return 0;
 }
 
 
-- 
2.51.1.dirty

Re: [syzbot] [jfs?] general protection fault in inode_set_ctime_current

[syzbot]

Hello,

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

Reported-by: syzbot+cd7590567cc388f064f3@syzkaller.appspotmail.com
Tested-by: syzbot+cd7590567cc388f064f3@syzkaller.appspotmail.com

Tested on:

commit:         fd575722 Merge tag 'sched_ext-for-6.18-rc3-fixes' of g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10aa832f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=41ad820f608cb833
dashboard link: https://syzkaller.appspot.com/bug?extid=cd7590567cc388f064f3
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1749ef34580000

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

Re: [syzbot] [jfs?] general protection fault in inode_set_ctime_current

[syzbot]

Hello,

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

Reported-by: syzbot+cd7590567cc388f064f3@syzkaller.appspotmail.com
Tested-by: syzbot+cd7590567cc388f064f3@syzkaller.appspotmail.com

Tested on:

commit:         fd575722 Merge tag 'sched_ext-for-6.18-rc3-fixes' of g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=130c432f980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=41ad820f608cb833
dashboard link: https://syzkaller.appspot.com/bug?extid=cd7590567cc388f064f3
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=14b04704580000

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

Re: [syzbot] [jfs?] general protection fault in inode_set_ctime_current

[syzbot]

Hello,

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

Reported-by: syzbot+cd7590567cc388f064f3@syzkaller.appspotmail.com
Tested-by: syzbot+cd7590567cc388f064f3@syzkaller.appspotmail.com

Tested on:

commit:         8eefed8f Merge tag 'nfsd-6.18-2' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=131d3d42580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=41ad820f608cb833
dashboard link: https://syzkaller.appspot.com/bug?extid=cd7590567cc388f064f3
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
patch:          https://syzkaller.appspot.com/x/patch.diff?x=12c4f614580000

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