| Message ID | 20180530125118.25274-2-jack@suse.cz |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | e2fsprogs: Handle s_inodes_count overflow better | expand |
On May 30, 2018, at 6:51 AM, Jan Kara <jack@suse.cz> wrote: > > If blocks count is exactly 1<<32, then the code computing number of > inode count in ext2fs_initialize() will overflow and set number of > inodes to 0 (which will be later fixed up to EXT2_FIRST_INODE(super)+1). > Fix the off-by-one bug in the check. > > Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Andreas Dilger <adilger@dilger.ca> > --- > lib/ext2fs/initialize.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c > index dbe798b27826..e1eff22eac33 100644 > --- a/lib/ext2fs/initialize.c > +++ b/lib/ext2fs/initialize.c > @@ -295,7 +295,7 @@ retry: > i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize; > > if (ext2fs_has_feature_64bit(super) && > - (ext2fs_blocks_count(super) / i) > (1ULL << 32)) > + (ext2fs_blocks_count(super) / i) >= (1ULL << 32)) > set_field(s_inodes_count, ~0U); > else > set_field(s_inodes_count, ext2fs_blocks_count(super) / i); > -- > 2.13.6 > Cheers, Andreas
diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c index dbe798b27826..e1eff22eac33 100644 --- a/lib/ext2fs/initialize.c +++ b/lib/ext2fs/initialize.c @@ -295,7 +295,7 @@ retry: i = fs->blocksize >= 4096 ? 1 : 4096 / fs->blocksize; if (ext2fs_has_feature_64bit(super) && - (ext2fs_blocks_count(super) / i) > (1ULL << 32)) + (ext2fs_blocks_count(super) / i) >= (1ULL << 32)) set_field(s_inodes_count, ~0U); else set_field(s_inodes_count, ext2fs_blocks_count(super) / i);
If blocks count is exactly 1<<32, then the code computing number of inode count in ext2fs_initialize() will overflow and set number of inodes to 0 (which will be later fixed up to EXT2_FIRST_INODE(super)+1). Fix the off-by-one bug in the check. Signed-off-by: Jan Kara <jack@suse.cz> --- lib/ext2fs/initialize.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)