diff options
| author | Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> | 2024-03-01 16:04:06 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-06 17:38:48 +0300 |
| commit | 7d930a4da17958f869ef679ee0e4a8729337affc (patch) | |
| tree | a62b589a3d1691afb220ae3d5a109cae15c6777e | |
| parent | 5941a90c55d3bfba732b32208d58d997600b44ef (diff) | |
| download | linux-7d930a4da17958f869ef679ee0e4a8729337affc.tar.xz | |
tomoyo: fix UAF write bug in tomoyo_write_control()
commit 2f03fc340cac9ea1dc63cbf8c93dd2eb0f227815 upstream.
Since tomoyo_write_control() updates head->write_buf when write()
of long lines is requested, we need to fetch head->write_buf after
head->io_sem is held. Otherwise, concurrent write() requests can
cause use-after-free-write and double-free problems.
Reported-by: Sam Sun <samsun1006219@gmail.com>
Closes: https://lkml.kernel.org/r/CAEkJfYNDspuGxYx5kym8Lvp--D36CMDUErg4rxfWFJuPbbji8g@mail.gmail.com
Fixes: bd03a3e4c9a9 ("TOMOYO: Add policy namespace support.")
Cc: <stable@vger.kernel.org> # Linux 3.1+
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | security/tomoyo/common.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/security/tomoyo/common.c b/security/tomoyo/common.c index 5c64927bf2b3..9a66e5826f25 100644 --- a/security/tomoyo/common.c +++ b/security/tomoyo/common.c @@ -2657,13 +2657,14 @@ ssize_t tomoyo_write_control(struct tomoyo_io_buffer *head, { int error = buffer_len; size_t avail_len = buffer_len; - char *cp0 = head->write_buf; + char *cp0; int idx; if (!head->write) return -EINVAL; if (mutex_lock_interruptible(&head->io_sem)) return -EINTR; + cp0 = head->write_buf; head->read_user_buf_avail = 0; idx = tomoyo_read_lock(); /* Read a line and dispatch it to the policy handler. */ |