lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:   Wed, 27 Feb 2019 22:36:25 +0800
From:   zerons <sironhide0null@...il.com>
To:     ast@...nel.org, daniel@...earbox.net
Cc:     netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        Peng Sun <sironhide0null@...il.com>
Subject: [PATCH] bpf: drop refcount if bpf_map_new_fd() fails in map_create()

In bpf/syscall.c, map_create() first set map->usercnt to 1, a file descriptor is
supposed to return to userspace. When bpf_map_new_fd() fails, drop the refcount.

Signed-off-by: Peng Sun <sironhide0null@...il.com>
---
 kernel/bpf/syscall.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index cf5040f..1c4f1c4 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -558,12 +558,12 @@ static int map_create(union bpf_attr *attr)
 	err = bpf_map_new_fd(map, f_flags);
 	if (err < 0) {
 		/* failed to allocate fd.
-		 * bpf_map_put() is needed because the above
+		 * bpf_map_put_with_uref() is needed because the above
 		 * bpf_map_alloc_id() has published the map
 		 * to the userspace and the userspace may
 		 * have refcnt-ed it through BPF_MAP_GET_FD_BY_ID.
 		 */
-		bpf_map_put(map);
+		bpf_map_put_with_uref(map);
 		return err;
 	}

--
2.7.4

Powered by blists - more mailing lists