From 8ed814602876bec9bad2649ca17f34b499357a1c Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Mon, 6 Jan 2014 21:28:15 +0900 Subject: [PATCH] SELinux: Fix memory leak upon loading policy Hello. I got below leak with linux-3.10.0-54.0.1.el7.x86_64 . [ 681.903890] kmemleak: 5538 new suspected memory leaks (see /sys/kernel/debug/kmemleak) Below is a patch, but I don't know whether we need special handing for undoing ebitmap_set_bit() call. ---------- >>From fe97527a90fe95e2239dfbaa7558f0ed559c0992 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Mon, 6 Jan 2014 16:30:21 +0900 Subject: [PATCH] SELinux: Fix memory leak upon loading policy Commit 2463c26d "SELinux: put name based create rules in a hashtable" did not check return value from hashtab_insert() in filename_trans_read(). It leaks memory if hashtab_insert() returns error. unreferenced object 0xffff88005c9160d0 (size 8): comm "systemd", pid 1, jiffies 4294688674 (age 235.265s) hex dump (first 8 bytes): 57 0b 00 00 6b 6b 6b a5 W...kkk. backtrace: [] kmemleak_alloc+0x4e/0xb0 [] kmem_cache_alloc_trace+0x12e/0x360 [] policydb_read+0xd1d/0xf70 [] security_load_policy+0x6c/0x500 [] sel_write_load+0xac/0x750 [] vfs_write+0xc0/0x1f0 [] SyS_write+0x4c/0xa0 [] system_call_fastpath+0x16/0x1b [] 0xffffffffffffffff However, we should not return EEXIST error to the caller, or the systemd will show below message and the boot sequence freezes. systemd[1]: Failed to load SELinux policy. Freezing. Signed-off-by: Tetsuo Handa Acked-by: Eric Paris Cc: stable@vger.kernel.org Signed-off-by: Paul Moore --- security/selinux/ss/policydb.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index dc4011643b55..c0f498842129 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -1995,7 +1995,19 @@ static int filename_trans_read(struct policydb *p, void *fp) if (rc) goto out; - hashtab_insert(p->filename_trans, ft, otype); + rc = hashtab_insert(p->filename_trans, ft, otype); + if (rc) { + /* + * Do not return -EEXIST to the caller, or the system + * will not boot. + */ + if (rc != -EEXIST) + goto out; + /* But free memory to avoid memory leak. */ + kfree(ft); + kfree(name); + kfree(otype); + } } hash_eval(p->filename_trans, "filenametr"); return 0;