The patch titled Subject: nilfs2: fix inode number range checks has been added to the -mm mm-hotfixes-unstable branch. Its filename is nilfs2-fix-inode-number-range-checks.patch
This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...
This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------ From: Ryusuke Konishi konishi.ryusuke@gmail.com Subject: nilfs2: fix inode number range checks Date: Sun, 23 Jun 2024 14:11:33 +0900
Patch series "nilfs2: fix potential issues related to reserved inodes".
This series fixes one use-after-free issue reported by syzbot, caused by nilfs2's internal inode being exposed in the namespace on a corrupted filesystem, and a couple of flaws that cause problems if the starting number of non-reserved inodes written in the on-disk super block is intentionally (or corruptly) changed from its default value.
This patch (of 3):
In the current implementation of nilfs2, "nilfs->ns_first_ino", which gives the first non-reserved inode number, is read from the superblock, but its lower limit is not checked.
As a result, if a number that overlaps with the inode number range of reserved inodes such as the root directory or metadata files is set in the super block parameter, the inode number test macros (NILFS_MDT_INODE and NILFS_VALID_INODE) will not function properly.
In addition, these test macros use left bit-shift calculations using with the inode number as the shift count via the BIT macro, but the result of a shift calculation that exceeds the bit width of an integer is undefined in the C specification, so if "ns_first_ino" is set to a large value other than the default value NILFS_USER_INO (=11), the macros may potentially malfunction depending on the environment.
Fix these issues by checking the lower bound of "nilfs->ns_first_ino" and by preventing bit shifts equal to or greater than the NILFS_USER_INO constant in the inode number test macros.
Also, change the type of "ns_first_ino" from signed integer to unsigned integer to avoid the need for type casting in comparisons such as the lower bound check introduced this time.
Link: https://lkml.kernel.org/r/20240623051135.4180-1-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/20240623051135.4180-2-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi konishi.ryusuke@gmail.com Cc: Hillf Danton hdanton@sina.com Cc: Jan Kara jack@suse.cz Cc: Matthew Wilcox (Oracle) willy@infradead.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
fs/nilfs2/nilfs.h | 5 +++-- fs/nilfs2/the_nilfs.c | 6 ++++++ fs/nilfs2/the_nilfs.h | 2 +- 3 files changed, 10 insertions(+), 3 deletions(-)
--- a/fs/nilfs2/nilfs.h~nilfs2-fix-inode-number-range-checks +++ a/fs/nilfs2/nilfs.h @@ -116,9 +116,10 @@ enum { #define NILFS_FIRST_INO(sb) (((struct the_nilfs *)sb->s_fs_info)->ns_first_ino)
#define NILFS_MDT_INODE(sb, ino) \ - ((ino) < NILFS_FIRST_INO(sb) && (NILFS_MDT_INO_BITS & BIT(ino))) + ((ino) < NILFS_USER_INO && (NILFS_MDT_INO_BITS & BIT(ino))) #define NILFS_VALID_INODE(sb, ino) \ - ((ino) >= NILFS_FIRST_INO(sb) || (NILFS_SYS_INO_BITS & BIT(ino))) + ((ino) >= NILFS_FIRST_INO(sb) || \ + ((ino) < NILFS_USER_INO && (NILFS_SYS_INO_BITS & BIT(ino))))
/** * struct nilfs_transaction_info: context information for synchronization --- a/fs/nilfs2/the_nilfs.c~nilfs2-fix-inode-number-range-checks +++ a/fs/nilfs2/the_nilfs.c @@ -452,6 +452,12 @@ static int nilfs_store_disk_layout(struc }
nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino); + if (nilfs->ns_first_ino < NILFS_USER_INO) { + nilfs_err(nilfs->ns_sb, + "too small lower limit for non-reserved inode numbers: %u", + nilfs->ns_first_ino); + return -EINVAL; + }
nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment); if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) { --- a/fs/nilfs2/the_nilfs.h~nilfs2-fix-inode-number-range-checks +++ a/fs/nilfs2/the_nilfs.h @@ -182,7 +182,7 @@ struct the_nilfs { unsigned long ns_nrsvsegs; unsigned long ns_first_data_block; int ns_inode_size; - int ns_first_ino; + unsigned int ns_first_ino; u32 ns_crc_seed;
/* /sys/fs/<nilfs>/<device> */ _
Patches currently in -mm which might be from konishi.ryusuke@gmail.com are
nilfs2-fix-inode-number-range-checks.patch nilfs2-add-missing-check-for-inode-numbers-on-directory-entries.patch nilfs2-fix-incorrect-inode-allocation-from-reserved-inodes.patch nilfs2-prepare-backing-device-folios-for-writing-after-adding-checksums.patch nilfs2-do-not-call-inode_attach_wb-directly.patch