Messages in this thread | | | Date | Mon, 20 Dec 2010 11:30:25 +0100 (CET) | From | Lukas Czerner <> | Subject | Re: [PATCH] ext4: fix possible overflow in ext4_trim_fs() |
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On Thu, 25 Nov 2010, Lukas Czerner wrote:
> When determining last group through ext4_get_group_no_and_offset() the > result may be wrong in cases when range->start and range-len are too > big, because it may overflow when summing up those two numbers. > > Fix that by checking range->len and limit its value to > ext4_blocks_count(). This commit was tested by myself with expected > result. > > Signed-off-by: Lukas Czerner <lczerner@redhat.com> > --- > fs/ext4/mballoc.c | 4 ++++ > 1 files changed, 4 insertions(+), 0 deletions(-) > > diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c > index 5b4d4e3..7b05d92 100644 > --- a/fs/ext4/mballoc.c > +++ b/fs/ext4/mballoc.c > @@ -4819,6 +4819,7 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) > ext4_group_t group, ngroups = ext4_get_groups_count(sb); > ext4_grpblk_t cnt = 0, first_block, last_block; > uint64_t start, len, minlen, trimmed; > + ext4_fsblk_t blocks_count = ext4_blocks_count(EXT4_SB(sb)->s_es); > int ret = 0; > > start = range->start >> sb->s_blocksize_bits; > @@ -4826,6 +4827,9 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) > minlen = range->minlen >> sb->s_blocksize_bits; > trimmed = 0; > > + if (len > blocks_count) > + len = blocks_count - start; > + > if (unlikely(minlen > EXT4_BLOCKS_PER_GROUP(sb))) > return -EINVAL; > >
Hi Ted,
what is the status of this patch ?
-Lukas
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