fix: potentially printing wrong error message (#321)

it's possible for the close() calls to override the errno resulting in
incorrect error message being printed.

call error() immediately to avoid such possibilities.

also refactor a couple conditions to avoid doing multiple checks.

Reviewed-on: https://codeberg.org/nsxiv/nsxiv/pulls/321
Reviewed-by: Berke Kocaoğlu <berke.kocaoglu@metu.edu.tr>
This commit is contained in:
NRK 2022-06-25 08:21:05 +02:00
parent 9812d601c1
commit 658a935c04
2 changed files with 17 additions and 22 deletions

2
main.c
View File

@ -567,8 +567,8 @@ static bool run_key_handler(const char *key, unsigned int mask)
if (pfd.writefd < 0)
return false;
if ((pfs = fdopen(pfd.writefd, "w")) == NULL) {
close(pfd.writefd);
error(0, errno, "open pipe");
close(pfd.writefd);
return false;
}

37
util.c
View File

@ -233,8 +233,7 @@ spawn_t spawn(const char *cmd, char *const argv[], unsigned int flags)
{
pid_t pid;
spawn_t status = { -1, -1, -1 };
int pfd_read[2] = { -1, -1 };
int pfd_write[2] = { -1, -1 };
int pfd_read[2] = { -1, -1 }, pfd_write[2] = { -1, -1 };
const bool r = flags & X_READ;
const bool w = flags & X_WRITE;
@ -247,16 +246,18 @@ spawn_t spawn(const char *cmd, char *const argv[], unsigned int flags)
}
if (w && pipe(pfd_write) < 0) {
error(0, errno, "pipe: %s", cmd);
if (r) {
close(pfd_read[0]);
close(pfd_read[1]);
}
error(0, errno, "pipe: %s", cmd);
return status;
}
if ((pid = fork()) == 0) {
bool err = (r && dup2(pfd_read[1], 1) < 0) || (w && dup2(pfd_write[0], 0) < 0);
if ((pid = fork()) == 0) { /* in child */
if ((r && dup2(pfd_read[1], 1) < 0) || (w && dup2(pfd_write[0], 0) < 0))
error(EXIT_FAILURE, errno, "dup2: %s", cmd);
if (r) {
close(pfd_read[0]);
close(pfd_read[1]);
@ -265,29 +266,23 @@ spawn_t spawn(const char *cmd, char *const argv[], unsigned int flags)
close(pfd_write[0]);
close(pfd_write[1]);
}
if (err)
error(EXIT_FAILURE, errno, "dup2: %s", cmd);
execv(cmd, argv);
error(EXIT_FAILURE, errno, "exec: %s", cmd);
} else if (pid < 0) { /* fork failed */
error(0, errno, "fork: %s", cmd);
if (r)
close(pfd_read[0]);
if (w)
close(pfd_write[1]);
} else { /* in parent */
status.pid = pid;
status.readfd = pfd_read[0];
status.writefd = pfd_write[1];
}
if (r)
close(pfd_read[1]);
if (w)
close(pfd_write[0]);
if (pid < 0) {
if (r)
close(pfd_read[0]);
if (w)
close(pfd_write[1]);
error(0, errno, "fork: %s", cmd);
return status;
}
status.pid = pid;
status.readfd = pfd_read[0];
status.writefd = pfd_write[1];
return status;
}