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authorMasami Hiramatsu <mhiramat@redhat.com>2010-01-08 17:42:38 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2010-01-11 12:34:04 -0500
commit8767ba2796a1c894e6d9524584a26a8224f0543d (patch)
treecefe04f3420ae11d46c4badbd1d3b2993da156b7 /kernel
parent42d53b4ff7d61487d18274ebdf1f70c1aef6f122 (diff)
kmod: fix resource leak in call_usermodehelper_pipe()
Fix resource (write-pipe file) leak in call_usermodehelper_pipe(). When call_usermodehelper_exec() fails, write-pipe file is opened and call_usermodehelper_pipe() just returns an error. Since it is hard for caller to determine whether the error occured when opening the pipe or executing the helper, the caller cannot close the pipe by themselves. I've found this resoruce leak when testing coredump. You can check how the resource leaks as below; $ echo "|nocommand" > /proc/sys/kernel/core_pattern $ ulimit -c unlimited $ while [ 1 ]; do ./segv; done &> /dev/null & $ cat /proc/meminfo (<- repeat it) where segv.c is; //----- int main () { char *p = 0; *p = 1; } //----- This patch closes write-pipe file if call_usermodehelper_exec() failed. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/kmod.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 25b103190364..bf0e231d9702 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -520,13 +520,15 @@ int call_usermodehelper_pipe(char *path, char **argv, char **envp,
520 return -ENOMEM; 520 return -ENOMEM;
521 521
522 ret = call_usermodehelper_stdinpipe(sub_info, filp); 522 ret = call_usermodehelper_stdinpipe(sub_info, filp);
523 if (ret < 0) 523 if (ret < 0) {
524 goto out; 524 call_usermodehelper_freeinfo(sub_info);
525 return ret;
526 }
525 527
526 return call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC); 528 ret = call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC);
529 if (ret < 0) /* Failed to execute helper, close pipe */
530 filp_close(*filp, NULL);
527 531
528 out:
529 call_usermodehelper_freeinfo(sub_info);
530 return ret; 532 return ret;
531} 533}
532EXPORT_SYMBOL(call_usermodehelper_pipe); 534EXPORT_SYMBOL(call_usermodehelper_pipe);