aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorNeel Chauhan <nc@FreeBSD.org>2021-11-16 22:59:26 +0000
committerNeel Chauhan <nc@FreeBSD.org>2021-11-29 17:53:45 +0000
commit3dd3a395ba975d0fbe13320e6e69fb85b037da5e (patch)
tree7668e23a841e59f6a41a4387e6743308a3932ec6
parent1910048eb931bb749c42534a8f252d772c0719de (diff)
downloadsrc-3dd3a395ba975d0fbe13320e6e69fb85b037da5e.tar.gz
src-3dd3a395ba975d0fbe13320e6e69fb85b037da5e.zip
ext2: Check for e2fs_first_dblock in ext2_compute_sb_data()
This prevents a kernel panic on a damaged ext2 superblock. PR: 259107 Reported by: Robert Morris <rtm@lcs.mit.edu> Differential Revision: https://reviews.freebsd.org/D33029
-rw-r--r--sys/fs/ext2fs/ext2_vfsops.c10
1 files changed, 9 insertions, 1 deletions
diff --git a/sys/fs/ext2fs/ext2_vfsops.c b/sys/fs/ext2fs/ext2_vfsops.c
index 65f429949f55..0ab0327ae074 100644
--- a/sys/fs/ext2fs/ext2_vfsops.c
+++ b/sys/fs/ext2fs/ext2_vfsops.c
@@ -465,6 +465,13 @@ ext2_compute_sb_data(struct vnode *devvp, struct ext2fs *es,
int g_count = 0;
int error;
+ /* Check if first dblock is valid */
+ if (fs->e2fs->e2fs_bcount >= 1024 && fs->e2fs->e2fs_first_dblock) {
+ SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
+ "first dblock is invalid");
+ return (EINVAL);
+ }
+
/* Check checksum features */
if (EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_GDT_CSUM) &&
EXT2_HAS_RO_COMPAT_FEATURE(fs, EXT2F_ROCOMPAT_METADATA_CKSUM)) {
@@ -611,7 +618,8 @@ ext2_compute_sb_data(struct vnode *devvp, struct ext2fs *es,
return (EINVAL);
}
- if (le32toh(es->e2fs_first_dblock) >= fs->e2fs_bcount) {
+ if (le32toh(es->e2fs_first_dblock) != (fs->e2fs_bsize > 1024 ? 0 : 1) ||
+ le32toh(es->e2fs_first_dblock) >= fs->e2fs_bcount) {
SDT_PROBE1(ext2fs, , vfsops, ext2_compute_sb_data_error,
"first data block out of range");
return (EINVAL);