Randy Dunlap 8efb3733cb JFS: more checks for invalid superblock ... commit 3bef198f1b upstream. syzbot is feeding invalid superblock data to JFS for mount testing. JFS does not check several of the fields -- just assumes that they are good since the JFS_MAGIC and version fields are good. In this case (syzbot reproducer), we have s_l2bsize == 0xda0c, pad == 0xf045, and s_state == 0x50, all of which are invalid IMO. Having s_l2bsize == 0xda0c causes this UBSAN warning: UBSAN: shift-out-of-bounds in fs/jfs/jfs_mount.c:373:25 shift exponent -9716 is negative s_l2bsize can be tested for correctness. pad can be tested for non-0 and punted. s_state can be tested for its valid values and punted. Do those 3 tests and if any of them fails, report the superblock as invalid/corrupt and let fsck handle it. With this patch, chkSuper() says this when JFS_DEBUG is enabled: jfs_mount: Mount Failure: superblock is corrupt! Mount JFS Failure: -22 jfs_mount failed w/return code = -22 The obvious problem with this method is that next week there could be another syzbot test that uses different fields for invalid values, this making this like a game of whack-a-mole. syzkaller link: https://syzkaller.appspot.com/bug?extid=36315852ece4132ec193 Reported-by: syzbot+36315852ece4132ec193@syzkaller.appspotmail.com Reported-by: kernel test robot <lkp@intel.com> # v2 Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com> Cc: jfs-discussion@lists.sourceforge.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-03-07 11:27:42 +01:00
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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	fs/jfs: fix potential integer overflow on shift of a int	2021-03-03 18:22:44 +01:00
jfs_dmap.h	jfs: Fix array index bounds check in dbAdjTree	2020-12-29 13:47:08 +01:00
jfs_dtree.c
jfs_dtree.h
jfs_extent.c
jfs_extent.h
jfs_filsys.h	JFS: more checks for invalid superblock	2021-03-07 11:27:42 +01:00
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: more checks for invalid superblock	2021-03-07 11:27:42 +01:00
jfs_superblock.h
jfs_txnmgr.c	jfs: fix bogus variable self-initialization	2020-01-27 14:46:26 +01:00
jfs_txnmgr.h
jfs_types.h
jfs_umount.c
jfs_unicode.c
jfs_unicode.h
jfs_uniupr.c
jfs_xattr.h
jfs_xtree.c
jfs_xtree.h
Kconfig
Makefile
namei.c
resize.c
super.c
symlink.c
xattr.c