[patch 30/31] fix deadlock in audit_log_task_context()

Greg KH
2007-03-19T21:43:50Z

[-- Attachment #1: fix-deadlock-in-audit_log_task_context.patch --]
[-- Type: text/plain, Size: 1553 bytes --]

-stable review patch. If anyone has any objections, please let us know.

------------------

From: Al Viro <viro@ftp.linux.org.uk>

[PATCH] fix deadlock in audit_log_task_context()

GFP_KERNEL allocations in non-blocking context; fixed by killing
an idiotic use of security_getprocattr().

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Cc: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
kernel/auditsc.c | 24 +++++++++++-------------
1 file changed, 11 insertions(+), 13 deletions(-)

--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -734,28 +734,26 @@ static inline void audit_free_context(st
void audit_log_task_context(struct audit_buffer *ab)
{
char *ctx = NULL;
- ssize_t len = 0;
+ unsigned len;
+ int error;
+ u32 sid;

- len = security_getprocattr(current, "current", NULL, 0);
- if (len < 0) {
- if (len != -EINVAL)
+ selinux_get_task_sid(current, &sid);
+ if (!sid)
+ return;
+
+ error = selinux_sid_to_string(sid, &ctx, &len);
+ if (error) {
+ if (error != -EINVAL)
goto error_path;
return;
}

- ctx = kmalloc(len, GFP_KERNEL);
- if (!ctx)
- goto error_path;
-
- len = security_getprocattr(current, "current", ctx, len);
- if (len < 0 )
- goto error_path;
-
audit_log_format(ab, " subj=%s", ctx);
+ kfree(ctx);
return;

error_path:
- kfree(ctx);
audit_panic("error in audit_log_task_context");
return;
}

--