2019-06-24 14:10:30

by Dan Carpenter

Subject: [bug report] ext4: optimize case-insensitive lookups

Hello Gabriel Krisman Bertazi,

The patch 3ae72562ad91: "ext4: optimize case-insensitive lookups"
from Jun 19, 2019, leads to the following static checker warning:

fs/ext4/namei.c:1311 ext4_fname_setup_ci_filename()
warn: 'cf_name->len' unsigned <= 0

fs/ext4/namei.c
1296 void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
1297 struct fscrypt_str *cf_name)
1298 {
1299 if (!IS_CASEFOLDED(dir)) {
1300 cf_name->name = NULL;
1301 return;
1302 }
1303
1304 cf_name->name = kmalloc(EXT4_NAME_LEN, GFP_NOFS);
1305 if (!cf_name->name)
1306 return;
1307
1308 cf_name->len = utf8_casefold(EXT4_SB(dir->i_sb)->s_encoding,
1309 iname, cf_name->name,
1310 EXT4_NAME_LEN);

utf8_casefold() returns negative error codes

1311 if (cf_name->len <= 0) {

but "cf_name->len" is a u32.

1312 kfree(cf_name->name);
1313 cf_name->name = NULL;
1314 }
1315 }


regards,
dan carpenter

2019-06-28 20:20:02

by Gabriel Krisman Bertazi

Subject: [PATCH] ext4: Fix coverity warning on error path of filename setup

Dan Carpenter <[email protected]> writes:

> Hello Gabriel Krisman Bertazi,
>
> The patch 3ae72562ad91: "ext4: optimize case-insensitive lookups"
> from Jun 19, 2019, leads to the following static checker warning:

Hi,

The patch below should fix this issue.

-- >8 --
Subject: [PATCH] ext4: Fix coverity warning on error path of filename setup

Fix the following coverity warning reported by Dan Carpenter:

fs/ext4/namei.c:1311 ext4_fname_setup_ci_filename()
warn: 'cf_name->len' unsigned <= 0

Fixes: 3ae72562ad91 ("ext4: optimize case-insensitive lookups")
Signed-off-by: Gabriel Krisman Bertazi <[email protected]>
Reported-by: Dan Carpenter <[email protected]>
---
fs/ext4/namei.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 4909ced4e672..898295286676 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1296,6 +1296,8 @@ int ext4_ci_compare(const struct inode *parent, const struct qstr *name,
void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
struct fscrypt_str *cf_name)
{
+ int len;
+
if (!IS_CASEFOLDED(dir)) {
cf_name->name = NULL;
return;
@@ -1305,13 +1307,16 @@ void ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
if (!cf_name->name)
return;

- cf_name->len = utf8_casefold(EXT4_SB(dir->i_sb)->s_encoding,
- iname, cf_name->name,
- EXT4_NAME_LEN);
- if (cf_name->len <= 0) {
+ len = utf8_casefold(EXT4_SB(dir->i_sb)->s_encoding,
+ iname, cf_name->name,
+ EXT4_NAME_LEN);
+ if (len <= 0) {
kfree(cf_name->name);
cf_name->name = NULL;
+ return;
}
+ cf_name->len = (unsigned) len;
+
}
#endif

--
2.20.1

2019-07-03 00:28:25

by Theodore Ts'o

Subject: Re: [PATCH] ext4: Fix coverity warning on error path of filename setup

On Fri, Jun 28, 2019 at 04:19:32PM -0400, Gabriel Krisman Bertazi wrote:
> Dan Carpenter <[email protected]> writes:
>
> > Hello Gabriel Krisman Bertazi,
> >
> > The patch 3ae72562ad91: "ext4: optimize case-insensitive lookups"
> > from Jun 19, 2019, leads to the following static checker warning:
>
> Hi,
>
> The patch below should fix this issue.
>
> -- >8 --
> Subject: [PATCH] ext4: Fix coverity warning on error path of filename setup
>
> Fix the following coverity warning reported by Dan Carpenter:
>
> fs/ext4/namei.c:1311 ext4_fname_setup_ci_filename()
> warn: 'cf_name->len' unsigned <= 0
>
> Fixes: 3ae72562ad91 ("ext4: optimize case-insensitive lookups")
> Signed-off-by: Gabriel Krisman Bertazi <[email protected]>
> Reported-by: Dan Carpenter <[email protected]>

Applied, thanks.

- Ted