The open() function returns -1 on error. openat() and open() initialize 'from' and 'to', and only 'from' validated with 'if' statement. If the initialization of variable 'to' fails, we should better check the value of 'to' and close 'from' to avoid possible file leak.
Fixes: 32ae976ed3b5 ("selftests/capabilities: Add tests for capability evolution") Signed-off-by: Ma Ke make24@iscas.ac.cn --- Found this error through static analysis. --- tools/testing/selftests/capabilities/test_execve.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/tools/testing/selftests/capabilities/test_execve.c b/tools/testing/selftests/capabilities/test_execve.c index 47bad7ddc5bc..de187eff177d 100644 --- a/tools/testing/selftests/capabilities/test_execve.c +++ b/tools/testing/selftests/capabilities/test_execve.c @@ -149,6 +149,10 @@ static void copy_fromat_to(int fromfd, const char *fromname, const char *toname) ksft_exit_fail_msg("open copy source - %s\n", strerror(errno));
int to = open(toname, O_CREAT | O_WRONLY | O_EXCL, 0700); + if (to == -1) { + close(from); + ksft_exit_fail_msg("open copy destination - %s\n", strerror(errno)); + }
while (true) { char buf[4096];
… openat() and open() initialize'from' and 'to', and only 'from' validated with 'if' statement.
Why do find such information helpful?
If theinitialization of variable 'to' fails,
The variable assignment will usually succeed. A stored return value would eventually indicate a failed function call.
we should better check the valueof 'to' and close 'from' to avoid possible file leak.
Please improve the change description with an imperative wording. https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
How do you think about to use a summary phrase like “Complete error handling in copy_fromat_to()”?
…
Found this error through static analysis.
* Were any special tools involved?
* Would you like to replace a duplicate marker line by a blank line?
Regards, Markus
On 6/26/24 01:20, Ma Ke wrote:
The open() function returns -1 on error. openat() and open() initialize 'from' and 'to', and only 'from' validated with 'if' statement. If the initialization of variable 'to' fails, we should better check the value of 'to' and close 'from' to avoid possible file leak.
Fixes: 32ae976ed3b5 ("selftests/capabilities: Add tests for capability evolution") Signed-off-by: Ma Ke make24@iscas.ac.cn
Found this error through static analysis.
Please add this line to change adding details about the tool you used to find this problem.
tools/testing/selftests/capabilities/test_execve.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/tools/testing/selftests/capabilities/test_execve.c b/tools/testing/selftests/capabilities/test_execve.c index 47bad7ddc5bc..de187eff177d 100644 --- a/tools/testing/selftests/capabilities/test_execve.c +++ b/tools/testing/selftests/capabilities/test_execve.c @@ -149,6 +149,10 @@ static void copy_fromat_to(int fromfd, const char *fromname, const char *toname) ksft_exit_fail_msg("open copy source - %s\n", strerror(errno)); int to = open(toname, O_CREAT | O_WRONLY | O_EXCL, 0700);
- if (to == -1) {
Changing this check to < instead of checking for just -1 can catch other error returns.
close(from);ksft_exit_fail_msg("open copy destination - %s\n", strerror(errno));- }
while (true) { char buf[4096];
thanks, -- Shuah
On 6/26/24 13:33, Shuah Khan wrote:
On 6/26/24 01:20, Ma Ke wrote:
The open() function returns -1 on error. openat() and open() initialize 'from' and 'to', and only 'from' validated with 'if' statement. If the initialization of variable 'to' fails, we should better check the value of 'to' and close 'from' to avoid possible file leak.
Fixes: 32ae976ed3b5 ("selftests/capabilities: Add tests for capability evolution") Signed-off-by: Ma Ke make24@iscas.ac.cn
Found this error through static analysis.
Please add this line to change adding details about the tool you used to find this problem.
tools/testing/selftests/capabilities/test_execve.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/tools/testing/selftests/capabilities/test_execve.c b/tools/testing/selftests/capabilities/test_execve.c index 47bad7ddc5bc..de187eff177d 100644 --- a/tools/testing/selftests/capabilities/test_execve.c +++ b/tools/testing/selftests/capabilities/test_execve.c @@ -149,6 +149,10 @@ static void copy_fromat_to(int fromfd, const char *fromname, const char *toname) ksft_exit_fail_msg("open copy source - %s\n", strerror(errno)); int to = open(toname, O_CREAT | O_WRONLY | O_EXCL, 0700); + if (to == -1) {
Changing this check to < instead of checking for just -1 can catch other error returns.
While you are fining this, can you fix this as well:
int from = openat(fromfd, fromname, O_RDONLY); if (from == -1) ksft_exit_fail_msg("open copy source - %s\n", strerror(errno));
Same change to check for <
thanks, -- Shuah
linux-kselftest-mirror@lists.linaro.org
-
Ma Ke -
Markus Elfring -
Shuah Khan