[syzbot report] UBSAN: array-index-out-of-bounds in fs/jfs/jfs_imap.c:886:2 index 524288 is out of range for type 'struct mutex[128]' CPU: 0 PID: 113 Comm: jfsCommit Not tainted 6.9.0-rc5-syzkaller-00036-g9d1ddab261f3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 ubsan_epilogue lib/ubsan.c:231 [inline] __ubsan_handle_out_of_bounds+0x121/0x150 lib/ubsan.c:429 diFree+0x21c3/0x2fb0 fs/jfs/jfs_imap.c:886 jfs_evict_inode+0x32d/0x440 fs/jfs/inode.c:156 evict+0x2a8/0x630 fs/inode.c:667 txUpdateMap+0x829/0x9f0 fs/jfs/jfs_txnmgr.c:2367 txLazyCommit fs/jfs/jfs_txnmgr.c:2664 [inline] jfs_lazycommit+0x49a/0xb80 fs/jfs/jfs_txnmgr.c:2733 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> ---[ end trace ]--- Kernel panic - not syncing: UBSAN: panic_on_warn set ... CPU: 1 PID: 113 Comm: jfsCommit Not tainted 6.9.0-rc5-syzkaller-00036-g9d1ddab261f3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 panic+0x349/0x860 kernel/panic.c:348 check_panic_on_warn+0x86/0xb0 kernel/panic.c:241 ubsan_epilogue lib/ubsan.c:236 [inline] __ubsan_handle_out_of_bounds+0x141/0x150 lib/ubsan.c:429 diFree+0x21c3/0x2fb0 fs/jfs/jfs_imap.c:886 jfs_evict_inode+0x32d/0x440 fs/jfs/inode.c:156 evict+0x2a8/0x630 fs/inode.c:667 txUpdateMap+0x829/0x9f0 fs/jfs/jfs_txnmgr.c:2367 txLazyCommit fs/jfs/jfs_txnmgr.c:2664 [inline] jfs_lazycommit+0x49a/0xb80 fs/jfs/jfs_txnmgr.c:2733 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Kernel Offset: disabled Rebooting in 86400 seconds.. =========================================================== Due to overflow, a value that is too large is entered into the agno value. Therefore, we need to add code to check the agno value. Reported-by: syzbot+241c815bda521982cb49@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Jeongjun Park <aha310510@xxxxxxxxx> --- fs/jfs/jfs_imap.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/jfs/jfs_imap.c b/fs/jfs/jfs_imap.c index 2ec35889ad24..0aac083bc0db 100644 --- a/fs/jfs/jfs_imap.c +++ b/fs/jfs/jfs_imap.c @@ -881,6 +881,11 @@ int diFree(struct inode *ip) */ agno = BLKTOAG(JFS_IP(ip)->agstart, JFS_SBI(ip->i_sb)); + if(agno >= MAXAG || agno < 0){ + jfs_error(ip->i_sb, "invalid array index (0 <= agno < MAXAG), agno = %d\n", agno); + return -ENOMEM; + } + /* Lock the AG specific inode map information */ AG_LOCK(imap, agno); -- 2.34.1