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37bfb464dd
Validate db_agheight, db_agwidth, and db_agstart in dbMount to catch
corrupted metadata early and avoid undefined behavior in dbAllocAG.
Limits are derived from L2LPERCTL, LPERCTL/MAXAG, and CTLTREESIZE:
- agheight: 0 to L2LPERCTL/2 (0 to 5) ensures shift
(L2LPERCTL - 2*agheight) >= 0.
- agwidth: 1 to min(LPERCTL/MAXAG, 2^(L2LPERCTL - 2*agheight))
ensures agperlev >= 1.
- Ranges: 1-8 (agheight 0-3), 1-4 (agheight 4), 1 (agheight 5).
- LPERCTL/MAXAG = 1024/128 = 8 limits leaves per AG;
2^(10 - 2*agheight) prevents division to 0.
- agstart: 0 to CTLTREESIZE-1 - agwidth*(MAXAG-1) keeps ti within
stree (size 1365).
- Ranges: 0-1237 (agwidth 1), 0-348 (agwidth 8).
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:1400:9
shift exponent -335544310 is negative
CPU: 0 UID: 0 PID: 5822 Comm: syz-executor130 Not tainted 6.14.0-rc5-syzkaller #0
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
ubsan_epilogue lib/ubsan.c:231 [inline]
__ubsan_handle_shift_out_of_bounds+0x3c8/0x420 lib/ubsan.c:468
dbAllocAG+0x1087/0x10b0 fs/jfs/jfs_dmap.c:1400
dbDiscardAG+0x352/0xa20 fs/jfs/jfs_dmap.c:1613
jfs_ioc_trim+0x45a/0x6b0 fs/jfs/jfs_discard.c:105
jfs_ioctl+0x2cd/0x3e0 fs/jfs/ioctl.c:131
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892
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
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Cc: stable@vger.kernel.org
Fixes:
|
||
|---|---|---|
| .. | ||
| acl.c | ||
| file.c | ||
| inode.c | ||
| ioctl.c | ||
| jfs_acl.h | ||
| jfs_btree.h | ||
| jfs_debug.c | ||
| jfs_debug.h | ||
| jfs_dinode.h | ||
| jfs_discard.c | ||
| jfs_discard.h | ||
| jfs_dmap.c | ||
| jfs_dmap.h | ||
| jfs_dtree.c | ||
| jfs_dtree.h | ||
| jfs_extent.c | ||
| jfs_extent.h | ||
| jfs_filsys.h | ||
| jfs_imap.c | ||
| jfs_imap.h | ||
| jfs_incore.h | ||
| jfs_inode.c | ||
| jfs_inode.h | ||
| jfs_lock.h | ||
| jfs_logmgr.c | ||
| jfs_logmgr.h | ||
| jfs_metapage.c | ||
| jfs_metapage.h | ||
| jfs_mount.c | ||
| jfs_superblock.h | ||
| jfs_txnmgr.c | ||
| jfs_txnmgr.h | ||
| jfs_types.h | ||
| jfs_umount.c | ||
| jfs_unicode.c | ||
| jfs_unicode.h | ||
| jfs_xattr.h | ||
| jfs_xtree.c | ||
| jfs_xtree.h | ||
| Kconfig | ||
| Makefile | ||
| namei.c | ||
| resize.c | ||
| super.c | ||
| symlink.c | ||
| xattr.c | ||