From fec6375320c6399c708fa9801f8cfbf950fee623 Mon Sep 17 00:00:00 2001 From: Gen Zhang Date: Wed, 12 Jun 2019 21:55:38 +0800 Subject: [PATCH] selinux: fix a missing-check bug in selinux_sb_eat_lsm_opts() In selinux_sb_eat_lsm_opts(), 'arg' is allocated by kmemdup_nul(). It returns NULL when fails. So 'arg' should be checked. And 'mnt_opts' should be freed when error. Signed-off-by: Gen Zhang Fixes: 99dbbb593fe6 ("selinux: rewrite selinux_sb_eat_lsm_opts()") Cc: Signed-off-by: Paul Moore --- security/selinux/hooks.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index b7db84c97882..fea66f6b31bf 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2625,10 +2625,11 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts) char *from = options; char *to = options; bool first = true; + int rc; while (1) { int len = opt_len(from); - int token, rc; + int token; char *arg = NULL; token = match_opt_prefix(from, len, &arg); @@ -2644,15 +2645,15 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts) *q++ = c; } arg = kmemdup_nul(arg, q - arg, GFP_KERNEL); + if (!arg) { + rc = -ENOMEM; + goto free_opt; + } } rc = selinux_add_opt(token, arg, mnt_opts); if (unlikely(rc)) { kfree(arg); - if (*mnt_opts) { - selinux_free_mnt_opts(*mnt_opts); - *mnt_opts = NULL; - } - return rc; + goto free_opt; } } else { if (!first) { // copy with preceding comma @@ -2670,6 +2671,13 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts) } *to = '\0'; return 0; + +free_opt: + if (*mnt_opts) { + selinux_free_mnt_opts(*mnt_opts); + *mnt_opts = NULL; + } + return rc; } static int selinux_sb_remount(struct super_block *sb, void *mnt_opts) -- 2.34.1