| Message ID | 20211210120359.394986-1-bernard@vivo.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Paul Moore |
| Headers | show |
| Series | [v3] security/selinux: fix potential memleak in error branch | expand |
On Fri, Dec 10, 2021 at 7:04 AM Bernard Zhao <bernard@vivo.com> wrote: > > This patch try to fix potential memleak in error branch. > > Signed-off-by: Bernard Zhao <bernard@vivo.com> > > Changes since V1: > *make it to be simpler to do the "(!s)" check before the "(!opts)" check. > > Changes since v2: > *add *mnt_opts = NULL after kfree(opt) to avoid double free risk. > --- > security/selinux/hooks.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) Hi Bernard, I apologize for the late response, this was lost in my inbox for some reason. Regardless, this looks fine to me so I'm merging it into selinux/next; thanks for your help. However, Ondrej made a few good suggestions about further improvements that could be made up at the LSM layer, I think it would be nice if you could look into that too. Thanks again for your help.
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 62d30c0a30c2..0d018f054dfb 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -983,18 +983,22 @@ static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb, static int selinux_add_opt(int token, const char *s, void **mnt_opts) { struct selinux_mnt_opts *opts = *mnt_opts; + bool is_alloc_opts = false; if (token == Opt_seclabel) /* eaten and completely ignored */ return 0; + if (!s) + return -ENOMEM; + if (!opts) { opts = kzalloc(sizeof(struct selinux_mnt_opts), GFP_KERNEL); if (!opts) return -ENOMEM; *mnt_opts = opts; + is_alloc_opts = true; } - if (!s) - return -ENOMEM; + switch (token) { case Opt_context: if (opts->context || opts->defcontext) @@ -1019,6 +1023,10 @@ static int selinux_add_opt(int token, const char *s, void **mnt_opts) } return 0; Einval: + if (is_alloc_opts) { + kfree(opts); + *mnt_opts = NULL; + } pr_warn(SEL_MOUNT_FAIL_MSG); return -EINVAL; }
This patch try to fix potential memleak in error branch. Signed-off-by: Bernard Zhao <bernard@vivo.com> Changes since V1: *make it to be simpler to do the "(!s)" check before the "(!opts)" check. Changes since v2: *add *mnt_opts = NULL after kfree(opt) to avoid double free risk. --- security/selinux/hooks.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)