| Message ID | 20201102172733.23444-3-jack@suse.cz (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | quota: Handle corrupted quota file better | expand |
On Nov 2, 2020, at 10:27 AM, Jan Kara <jack@suse.cz> wrote: > > Perform basic sanity checks of quota headers to avoid kernel crashes on > corrupted quota files. > > CC: stable@vger.kernel.org > Reported-by: syzbot+f816042a7ae2225f25ba@syzkaller.appspotmail.com > Signed-off-by: Jan Kara <jack@suse.cz> Looks reasonable. Reviewed-by: Andreas Dilger <adilger@dilger.ca> > --- > fs/quota/quota_v2.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/fs/quota/quota_v2.c b/fs/quota/quota_v2.c > index e69a2bfdd81c..c21106557a37 100644 > --- a/fs/quota/quota_v2.c > +++ b/fs/quota/quota_v2.c > @@ -157,6 +157,25 @@ static int v2_read_file_info(struct super_block *sb, int type) > qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk); > qinfo->dqi_ops = &v2r1_qtree_ops; > } > + ret = -EUCLEAN; > + /* Some sanity checks of the read headers... */ > + if ((loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits > > + i_size_read(sb_dqopt(sb)->files[type])) { > + quota_error(sb, "Number of blocks too big for quota file size (%llu > %llu).", > + (loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits, > + i_size_read(sb_dqopt(sb)->files[type])); > + goto out; > + } > + if (qinfo->dqi_free_blk >= qinfo->dqi_blocks) { > + quota_error(sb, "Free block number too big (%u >= %u).", > + qinfo->dqi_free_blk, qinfo->dqi_blocks); > + goto out; > + } > + if (qinfo->dqi_free_entry >= qinfo->dqi_blocks) { > + quota_error(sb, "Block with free entry too big (%u >= %u).", > + qinfo->dqi_free_entry, qinfo->dqi_blocks); > + goto out; > + } > ret = 0; > out: > up_read(&dqopt->dqio_sem); > -- > 2.16.4 > Cheers, Andreas
diff --git a/fs/quota/quota_v2.c b/fs/quota/quota_v2.c index e69a2bfdd81c..c21106557a37 100644 --- a/fs/quota/quota_v2.c +++ b/fs/quota/quota_v2.c @@ -157,6 +157,25 @@ static int v2_read_file_info(struct super_block *sb, int type) qinfo->dqi_entry_size = sizeof(struct v2r1_disk_dqblk); qinfo->dqi_ops = &v2r1_qtree_ops; } + ret = -EUCLEAN; + /* Some sanity checks of the read headers... */ + if ((loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits > + i_size_read(sb_dqopt(sb)->files[type])) { + quota_error(sb, "Number of blocks too big for quota file size (%llu > %llu).", + (loff_t)qinfo->dqi_blocks << qinfo->dqi_blocksize_bits, + i_size_read(sb_dqopt(sb)->files[type])); + goto out; + } + if (qinfo->dqi_free_blk >= qinfo->dqi_blocks) { + quota_error(sb, "Free block number too big (%u >= %u).", + qinfo->dqi_free_blk, qinfo->dqi_blocks); + goto out; + } + if (qinfo->dqi_free_entry >= qinfo->dqi_blocks) { + quota_error(sb, "Block with free entry too big (%u >= %u).", + qinfo->dqi_free_entry, qinfo->dqi_blocks); + goto out; + } ret = 0; out: up_read(&dqopt->dqio_sem);
Perform basic sanity checks of quota headers to avoid kernel crashes on corrupted quota files. CC: stable@vger.kernel.org Reported-by: syzbot+f816042a7ae2225f25ba@syzkaller.appspotmail.com Signed-off-by: Jan Kara <jack@suse.cz> --- fs/quota/quota_v2.c | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)