[syzbot] [jfs?] UBSAN: array-index-out-of-bounds in diNewExt

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: bee0e7762ad2 Merge tag 'for-linus-iommufd' of git://git.ke..
git tree: upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1088351ce80000
kernel config: https://syzkaller.appspot.com/x/.config?x=b45dfd882e46ec91
dashboard link: https://syzkaller.appspot.com/bug?extid=553d90297e6d2f50dbc7
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=122acc3ce80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=110a49b4e80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/af357ba4767f/disk-bee0e776.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ae4d50206171/vmlinux-bee0e776.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e12203376a9f/bzImage-bee0e776.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/d8974c833f6f/mount_0.gz

Bisection is inconclusive: the issue happens on the oldest tested release.

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=133caf54e80000
final oops: https://syzkaller.appspot.com/x/report.txt?x=10bcaf54e80000
console output: https://syzkaller.appspot.com/x/log.txt?x=173caf54e80000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+553d90...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 32768
================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_imap.c:2360:2
index -878706688 is out of range for type 'struct iagctl[128]'
CPU: 1 PID: 5065 Comm: syz-executor282 Not tainted 6.7.0-rc4-syzkaller-00009-gbee0e7762ad2 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:217 [inline]
__ubsan_handle_out_of_bounds+0x11c/0x150 lib/ubsan.c:348
diNewExt+0x3cf3/0x4000 fs/jfs/jfs_imap.c:2360
diAllocExt fs/jfs/jfs_imap.c:1949 [inline]
diAllocAG+0xbe8/0x1e50 fs/jfs/jfs_imap.c:1666
diAlloc+0x1d3/0x1760 fs/jfs/jfs_imap.c:1587
ialloc+0x8f/0x900 fs/jfs/jfs_inode.c:56
jfs_mkdir+0x1c5/0xb90 fs/jfs/namei.c:225
vfs_mkdir+0x2f1/0x4b0 fs/namei.c:4106
do_mkdirat+0x264/0x3a0 fs/namei.c:4129
__do_sys_mkdir fs/namei.c:4149 [inline]
__se_sys_mkdir fs/namei.c:4147 [inline]
__x64_sys_mkdir+0x6e/0x80 fs/namei.c:4147
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7fcb7e6a0b57
Code: ff ff 77 07 31 c0 c3 0f 1f 40 00 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 b8 53 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:00007ffd83023038 EFLAGS: 00000286 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007fcb7e6a0b57
RDX: 00000000000a1020 RSI: 00000000000001ff RDI: 0000000020000140
RBP: 0000000020000140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000286 R12: 00007ffd830230d0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
================================================================================


---
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.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection

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

[Edward Adam Davis]

please test array-index-out-of-bounds in diNewExt

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git bee0e7762ad2

diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c
index a037ee59e398..4e17e261de26 100644
--- a/fs/jfs/jfs_imap.c
+++ b/fs/jfs/jfs_imap.c
@@ -2179,6 +2179,11 @@ static int diNewExt(struct inomap * imap, struct iag * iagp, int extno)
/* get the ag and iag numbers for this iag.
*/
agno = BLKTOAG(le64_to_cpu(iagp->agstart), sbi);
+ printk("agno: %d, ipimap: %p, iagp: %p, sbi: %p, agl2s: %d\n",
+ agno, ipimap, iagp, sbi, sbi->bmap->db_agl2size);
+ if (agno > MAXAG)
+ return -EINVAL;
+
iagno = le32_to_cpu(iagp->iagnum);

/* check if this is the last free extent within the
@@ -2357,6 +2362,8 @@ static int diNewExt(struct inomap * imap, struct iag * iagp, int extno)

/* update the free and backed inode counts for the ag.
*/
+ printk("agno: %d, ipimap: %p, iagp: %p, sbi: %p, agl2s: %d\n",
+ agno, ipimap, iagp, sbi, sbi->bmap->db_agl2size);
imap->im_agctl[agno].numfree += (INOSPEREXT - 1);
imap->im_agctl[agno].numinos += INOSPEREXT;

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
UBSAN: array-index-out-of-bounds in diNewExt

loop0: detected capacity change from 0 to 32768

agno: -878706688, ipimap: ffff88806b342930, iagp: ffff888024d4f000, sbi: ffff888016657a00, agl2s: 13
agno: -878706688, ipimap: ffff88806b342930, iagp: ffff888024d4f000, sbi: ffff888016657a00, agl2s: 13
================================================================================
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_imap.c:2367:2

index -878706688 is out of range for type 'struct iagctl[128]'

CPU: 0 PID: 5481 Comm: syz-executor.0 Not tainted 6.7.0-rc4-syzkaller-00009-gbee0e7762ad2-dirty #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
ubsan_epilogue lib/ubsan.c:217 [inline]
__ubsan_handle_out_of_bounds+0x11c/0x150 lib/ubsan.c:348

diNewExt+0x3b39/0x3e00 fs/jfs/jfs_imap.c:2367

diAllocExt fs/jfs/jfs_imap.c:1949 [inline]
diAllocAG+0xbe8/0x1e50 fs/jfs/jfs_imap.c:1666
diAlloc+0x1d3/0x1760 fs/jfs/jfs_imap.c:1587
ialloc+0x8f/0x900 fs/jfs/jfs_inode.c:56
jfs_mkdir+0x1c5/0xb90 fs/jfs/namei.c:225
vfs_mkdir+0x2f1/0x4b0 fs/namei.c:4106
do_mkdirat+0x264/0x3a0 fs/namei.c:4129

__do_sys_mkdirat fs/namei.c:4144 [inline]
__se_sys_mkdirat fs/namei.c:4142 [inline]
__x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4142

do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x45/0x110 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x63/0x6b

RIP: 0033:0x7f857287b5e7
Code: 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8571bfdee8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f857287b5e7
RDX: 00000000000001ff RSI: 0000000020000140 RDI: 00000000ffffff9c
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020000140
R13: 00007f8571bfdf40 R14: 0000000000000000 R15: 0000000000000000
</TASK>
================================================================================


Tested on:

commit: bee0e776 Merge tag 'for-linus-iommufd' of git://git.ke..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=135fd132e80000

kernel config: https://syzkaller.appspot.com/x/.config?x=b45dfd882e46ec91
dashboard link: https://syzkaller.appspot.com/bug?extid=553d90297e6d2f50dbc7
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=10668e46e80000

[Edward Adam Davis]

please test array-index-out-of-bounds in diNewExt

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git bee0e7762ad2

diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c

index a037ee59e398..8fc28b655060 100644
--- a/fs/jfs/jfs_imap.c
+++ b/fs/jfs/jfs_imap.c
@@ -1341,6 +1341,7 @@ int diAlloc(struct inode *pip, bool dir, struct inode *ip)
*/
if (dir) {
agno = dbNextAG(JFS_SBI(pip->i_sb)->ipbmap);
+ printk("agno/dbNextAG: %d, %s\n", agno, __func__);
AG_LOCK(imap, agno);
goto tryag;
}
@@ -1356,6 +1357,7 @@ int diAlloc(struct inode *pip, bool dir, struct inode *ip)

/* get the ag number of this iag */
agno = BLKTOAG(JFS_IP(pip)->agstart, JFS_SBI(pip->i_sb));
+ printk("agno/agstart: %d, %s\n", agno, __func__);
dn_numag = JFS_SBI(pip->i_sb)->bmap->db_numag;
if (agno < 0 || agno > dn_numag)
return -EIO;
@@ -1584,6 +1586,7 @@ int diAlloc(struct inode *pip, bool dir, struct inode *ip)
/*
* try to allocate anywhere within the same AG as the parent inode.
*/
+ printk("agno: %d, %s\n", agno, __func__);
rc = diAllocAG(imap, agno, dir, ip);

AG_UNLOCK(imap, agno);
@@ -2179,6 +2182,9 @@ static int diNewExt(struct inomap * imap, struct iag * iagp, int extno)

/* get the ag and iag numbers for this iag.
*/
agno = BLKTOAG(le64_to_cpu(iagp->agstart), sbi);

+ if (agno > MAXAG || agno < 0)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:

kernel BUG in lbmIODone

BUG at fs/jfs/jfs_logmgr.c:2303 assert(bp->l_flag & lbmRELEASE)
------------[ cut here ]------------
kernel BUG at fs/jfs/jfs_logmgr.c:2303!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 22 Comm: ksoftirqd/1 Not tainted 6.7.0-rc4-syzkaller-00009-gbee0e7762ad2-dirty #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023

RIP: 0010:lbmIODone+0x16fa/0x1750 fs/jfs/jfs_logmgr.c:2303
Code: fe 07 90 0f 0b e8 e6 cf 78 fe 48 c7 c7 c0 73 a2 8b 48 c7 c6 c0 6e a2 8b ba ff 08 00 00 48 c7 c1 20 7d a2 8b e8 67 a8 fe 07 90 <0f> 0b e8 bf cf 78 fe 48 c7 c7 c0 73 a2 8b 48 c7 c6 c0 6e a2 8b ba
RSP: 0018:ffffc900001c7ad8 EFLAGS: 00010046
RAX: 000000000000003f RBX: 0000000000000020 RCX: f6d0cfb74fb3eb00
RDX: 0000000080000101 RSI: 0000000080000101 RDI: 0000000000000000
RBP: ffff8880278cb008 R08: ffffffff8171379c R09: 1ffff92000038efc
R10: dffffc0000000000 R11: fffff52000038efd R12: dffffc0000000000
R13: ffff8880278cb000 R14: ffff88807eb3da78 R15: 0000000000000246
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c0013fe000 CR3: 00000000702ba000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
req_bio_endio block/blk-mq.c:788 [inline]
blk_update_request+0x53f/0x1020 block/blk-mq.c:933
blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1056
blk_complete_reqs block/blk-mq.c:1131 [inline]
blk_done_softirq+0x103/0x150 block/blk-mq.c:1136
__do_softirq+0x2b8/0x939 kernel/softirq.c:553
run_ksoftirqd+0xc5/0x120 kernel/softirq.c:921
smpboot_thread_fn+0x530/0x9f0 kernel/smpboot.c:164
kthread+0x2d3/0x370 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:lbmIODone+0x16fa/0x1750 fs/jfs/jfs_logmgr.c:2303
Code: fe 07 90 0f 0b e8 e6 cf 78 fe 48 c7 c7 c0 73 a2 8b 48 c7 c6 c0 6e a2 8b ba ff 08 00 00 48 c7 c1 20 7d a2 8b e8 67 a8 fe 07 90 <0f> 0b e8 bf cf 78 fe 48 c7 c7 c0 73 a2 8b 48 c7 c6 c0 6e a2 8b ba
RSP: 0018:ffffc900001c7ad8 EFLAGS: 00010046
RAX: 000000000000003f RBX: 0000000000000020 RCX: f6d0cfb74fb3eb00
RDX: 0000000080000101 RSI: 0000000080000101 RDI: 0000000000000000
RBP: ffff8880278cb008 R08: ffffffff8171379c R09: 1ffff92000038efc
R10: dffffc0000000000 R11: fffff52000038efd R12: dffffc0000000000
R13: ffff8880278cb000 R14: ffff88807eb3da78 R15: 0000000000000246
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c0013fe000 CR3: 00000000702ba000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Tested on:

commit: bee0e776 Merge tag 'for-linus-iommufd' of git://git.ke..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

console output: https://syzkaller.appspot.com/x/log.txt?x=13272966e80000

kernel config: https://syzkaller.appspot.com/x/.config?x=b45dfd882e46ec91
dashboard link: https://syzkaller.appspot.com/bug?extid=553d90297e6d2f50dbc7
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=165f472ee80000

[Edward Adam Davis]

please test array-index-out-of-bounds in diNewExt

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git bee0e7762ad2

diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c

index a037ee59e398..b52f34e04f6a 100644

--- a/fs/jfs/jfs_imap.c
+++ b/fs/jfs/jfs_imap.c
@@ -1341,6 +1341,7 @@ int diAlloc(struct inode *pip, bool dir, struct inode *ip)
*/
if (dir) {
agno = dbNextAG(JFS_SBI(pip->i_sb)->ipbmap);
+ printk("agno/dbNextAG: %d, %s\n", agno, __func__);
AG_LOCK(imap, agno);
goto tryag;
}
@@ -1356,6 +1357,7 @@ int diAlloc(struct inode *pip, bool dir, struct inode *ip)

/* get the ag number of this iag */
agno = BLKTOAG(JFS_IP(pip)->agstart, JFS_SBI(pip->i_sb));
+ printk("agno/agstart: %d, %s\n", agno, __func__);
dn_numag = JFS_SBI(pip->i_sb)->bmap->db_numag;
if (agno < 0 || agno > dn_numag)
return -EIO;
@@ -1584,6 +1586,7 @@ int diAlloc(struct inode *pip, bool dir, struct inode *ip)
/*
* try to allocate anywhere within the same AG as the parent inode.
*/

+ printk("agno: %d, agstart: %llu, %s\n", agno, JFS_IP(pip)->agstart, __func__);

rc = diAllocAG(imap, agno, dir, ip);

AG_UNLOCK(imap, agno);

@@ -1919,6 +1922,7 @@ static int diAllocExt(struct inomap * imap, int agno, struct inode *ip)
}
iagp = (struct iag *) mp->data;
}
+ printk("iagno: %d, %llu, %s\n", iagno, iagp->agstart, __func__);

/* using the free extent summary map, find a free extent.
*/
@@ -2179,6 +2183,9 @@ static int diNewExt(struct inomap * imap, struct iag * iagp, int extno)

/* get the ag and iag numbers for this iag.
*/
agno = BLKTOAG(le64_to_cpu(iagp->agstart), sbi);
+ if (agno > MAXAG || agno < 0)

+ return -EIO;

[syzbot]

Hello,

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

Reported-and-tested-by: syzbot+553d90...@syzkaller.appspotmail.com

Tested on:

commit: bee0e776 Merge tag 'for-linus-iommufd' of git://git.ke..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

console output: https://syzkaller.appspot.com/x/log.txt?x=10fd0182e80000

kernel config: https://syzkaller.appspot.com/x/.config?x=b45dfd882e46ec91
dashboard link: https://syzkaller.appspot.com/bug?extid=553d90297e6d2f50dbc7
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

patch: https://syzkaller.appspot.com/x/patch.diff?x=15cf16fae80000

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

[Edward Adam Davis]

[Syz report]

[Analysis]
When the agstart is too large, it can cause agno overflow.

[Fix]
After obtaining agno, if the value is invalid, exit the subsequent process.

Reported-and-tested-by: syzbot+553d90...@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <ead...@qq.com>
---
fs/jfs/jfs_imap.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c
index a037ee59e398..cc5819b3ec9a 100644
--- a/fs/jfs/jfs_imap.c
+++ b/fs/jfs/jfs_imap.c
@@ -2179,6 +2179,9 @@ static int diNewExt(struct inomap * imap, struct iag * iagp, int extno)

/* get the ag and iag numbers for this iag.
*/
agno = BLKTOAG(le64_to_cpu(iagp->agstart), sbi);
+ if (agno > MAXAG || agno < 0)
+ return -EIO;
+
iagno = le32_to_cpu(iagp->iagnum);

/* check if this is the last free extent within the

--
2.43.0

[Dave Kleikamp]

Looks good. Applied.

Shaggy

[Dan Carpenter]

Hi Edward,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Edward-Adam-Davis/jfs-fix-array-index-out-of-bounds-in-diNewExt/20231212-095530
base: https://github.com/kleikamp/linux-shaggy jfs-next
patch link: https://lore.kernel.org/r/tencent_B86ECD2ECECC92A7ED86EF92D0064A499206%40qq.com
patch subject: [PATCH] jfs: fix array-index-out-of-bounds in diNewExt
config: i386-randconfig-141-20231212 (https://download.01.org/0day-ci/archive/20231214/202312142348...@intel.com/config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce: (https://download.01.org/0day-ci/archive/20231214/202312142348...@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <l...@intel.com>
| Reported-by: Dan Carpenter <dan.ca...@linaro.org>
| Closes: https://lore.kernel.org/r/202312142348...@intel.com/

New smatch warnings:
fs/jfs/jfs_imap.c:2213 diNewExt() error: buffer overflow 'imap->im_imap.in_agctl' 128 <= 128

Old smatch warnings:
fs/jfs/jfs_imap.c:2229 diNewExt() error: buffer overflow 'imap->im_imap.in_agctl' 128 <= 128
fs/jfs/jfs_imap.c:2304 diNewExt() error: buffer overflow 'imap->im_imap.in_agctl' 128 <= 128
fs/jfs/jfs_imap.c:2318 diNewExt() error: buffer overflow 'imap->im_imap.in_agctl' 128 <= 128
fs/jfs/jfs_imap.c:2330 diNewExt() error: buffer overflow 'imap->im_imap.in_agctl' 128 <= 128
fs/jfs/jfs_imap.c:2332 diNewExt() error: buffer overflow 'imap->im_imap.in_agctl' 128 <= 128
fs/jfs/jfs_imap.c:2363 diNewExt() error: buffer overflow 'imap->im_imap.in_agctl' 128 <= 128
fs/jfs/jfs_imap.c:2364 diNewExt() error: buffer overflow 'imap->im_imap.in_agctl' 128 <= 128

vim +2213 fs/jfs/jfs_imap.c

^1da177e4c3f41 Linus Torvalds 2005-04-16 2152 static int diNewExt(struct inomap * imap, struct iag * iagp, int extno)
^1da177e4c3f41 Linus Torvalds 2005-04-16 2153 {
^1da177e4c3f41 Linus Torvalds 2005-04-16 2154 int agno, iagno, fwd, back, freei = 0, sword, rc;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2155 struct iag *aiagp = NULL, *biagp = NULL, *ciagp = NULL;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2156 struct metapage *amp, *bmp, *cmp, *dmp;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2157 struct inode *ipimap;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2158 s64 blkno, hint;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2159 int i, j;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2160 u32 mask;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2161 ino_t ino;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2162 struct dinode *dp;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2163 struct jfs_sb_info *sbi;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2164
^1da177e4c3f41 Linus Torvalds 2005-04-16 2165 /* better have free extents.
^1da177e4c3f41 Linus Torvalds 2005-04-16 2166 */
^1da177e4c3f41 Linus Torvalds 2005-04-16 2167 if (!iagp->nfreeexts) {
eb8630d7d2fd13 Joe Perches 2013-06-04 2168 jfs_error(imap->im_ipimap->i_sb, "no free extents\n");
^1da177e4c3f41 Linus Torvalds 2005-04-16 2169 return -EIO;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2170 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 2171
^1da177e4c3f41 Linus Torvalds 2005-04-16 2172 /* get the inode map inode.
^1da177e4c3f41 Linus Torvalds 2005-04-16 2173 */
^1da177e4c3f41 Linus Torvalds 2005-04-16 2174 ipimap = imap->im_ipimap;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2175 sbi = JFS_SBI(ipimap->i_sb);
^1da177e4c3f41 Linus Torvalds 2005-04-16 2176
^1da177e4c3f41 Linus Torvalds 2005-04-16 2177 amp = bmp = cmp = NULL;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2178
^1da177e4c3f41 Linus Torvalds 2005-04-16 2179 /* get the ag and iag numbers for this iag.
^1da177e4c3f41 Linus Torvalds 2005-04-16 2180 */
^1da177e4c3f41 Linus Torvalds 2005-04-16 2181 agno = BLKTOAG(le64_to_cpu(iagp->agstart), sbi);
f93b91b82fcf16 Edward Adam Davis 2023-12-12 2182 if (agno > MAXAG || agno < 0)

The commit introduces this agno > MAXAG comparison. But Smatch says
that it should be agno >= MAXAG.

f93b91b82fcf16 Edward Adam Davis 2023-12-12 2183 return -EIO;
f93b91b82fcf16 Edward Adam Davis 2023-12-12 2184
^1da177e4c3f41 Linus Torvalds 2005-04-16 2185 iagno = le32_to_cpu(iagp->iagnum);
^1da177e4c3f41 Linus Torvalds 2005-04-16 2186
^1da177e4c3f41 Linus Torvalds 2005-04-16 2187 /* check if this is the last free extent within the
^1da177e4c3f41 Linus Torvalds 2005-04-16 2188 * iag. if so, the iag must be removed from the ag
25985edcedea63 Lucas De Marchi 2011-03-30 2189 * free extent list, so get the iags preceding and
^1da177e4c3f41 Linus Torvalds 2005-04-16 2190 * following the iag on this list.
^1da177e4c3f41 Linus Torvalds 2005-04-16 2191 */
^1da177e4c3f41 Linus Torvalds 2005-04-16 2192 if (iagp->nfreeexts == cpu_to_le32(1)) {
^1da177e4c3f41 Linus Torvalds 2005-04-16 2193 if ((fwd = le32_to_cpu(iagp->extfreefwd)) >= 0) {
^1da177e4c3f41 Linus Torvalds 2005-04-16 2194 if ((rc = diIAGRead(imap, fwd, &amp)))
^1da177e4c3f41 Linus Torvalds 2005-04-16 2195 return (rc);
^1da177e4c3f41 Linus Torvalds 2005-04-16 2196 aiagp = (struct iag *) amp->data;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2197 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 2198
^1da177e4c3f41 Linus Torvalds 2005-04-16 2199 if ((back = le32_to_cpu(iagp->extfreeback)) >= 0) {
^1da177e4c3f41 Linus Torvalds 2005-04-16 2200 if ((rc = diIAGRead(imap, back, &bmp)))
^1da177e4c3f41 Linus Torvalds 2005-04-16 2201 goto error_out;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2202 biagp = (struct iag *) bmp->data;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2203 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 2204 } else {
^1da177e4c3f41 Linus Torvalds 2005-04-16 2205 /* the iag has free extents. if all extents are free
^1da177e4c3f41 Linus Torvalds 2005-04-16 2206 * (as is the case for a newly allocated iag), the iag
^1da177e4c3f41 Linus Torvalds 2005-04-16 2207 * must be added to the ag free extent list, so get
^1da177e4c3f41 Linus Torvalds 2005-04-16 2208 * the iag at the head of the list in preparation for
^1da177e4c3f41 Linus Torvalds 2005-04-16 2209 * adding this iag to this list.
^1da177e4c3f41 Linus Torvalds 2005-04-16 2210 */
^1da177e4c3f41 Linus Torvalds 2005-04-16 2211 fwd = back = -1;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2212 if (iagp->nfreeexts == cpu_to_le32(EXTSPERIAG)) {
^1da177e4c3f41 Linus Torvalds 2005-04-16 @2213 if ((fwd = imap->im_agctl[agno].extfree) >= 0) {

If agno == MAXAG then we're out of bounds here.

^1da177e4c3f41 Linus Torvalds 2005-04-16 2214 if ((rc = diIAGRead(imap, fwd, &amp)))
^1da177e4c3f41 Linus Torvalds 2005-04-16 2215 goto error_out;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2216 aiagp = (struct iag *) amp->data;
^1da177e4c3f41 Linus Torvalds 2005-04-16 2217 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 2218 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 2219 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 2220
^1da177e4c3f41 Linus Torvalds 2005-04-16 2221 /* check if the iag has no free inodes. if so, the iag

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[Dave Kleikamp]

On 1/2/24 7:29AM, Dan Carpenter wrote:
> Hi Edward,
>
> kernel test robot noticed the following build warnings:
>
> https://git-scm.com/docs/git-format-patch#_base_tree_information]
>
> url: https://github.com/intel-lab-lkp/linux/commits/Edward-Adam-Davis/jfs-fix-array-index-out-of-bounds-in-diNewExt/20231212-095530
> base: https://github.com/kleikamp/linux-shaggy jfs-next
> patch link: https://lore.kernel.org/r/tencent_B86ECD2ECECC92A7ED86EF92D0064A499206%40qq.com
> patch subject: [PATCH] jfs: fix array-index-out-of-bounds in diNewExt
> config: i386-randconfig-141-20231212 (https://download.01.org/0day-ci/archive/20231214/202312142348...@intel.com/config)
> compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
> reproduce: (https://download.01.org/0day-ci/archive/20231214/202312142348...@intel.com/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <l...@intel.com>
> | Reported-by: Dan Carpenter <dan.ca...@linaro.org>
> | Closes: https://lore.kernel.org/r/202312142348...@intel.com/

I modified Edward's patch in the jfs-next branch with the corrected test.

Thanks for catching this.

Shaggy