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| author | Kees Cook <keescook@chromium.org> | 2013-09-10 21:40:43 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-09-17 07:39:27 -0700 |
| commit | 1ea12fef83c3269eb7ba04f1d20db00c581515b2 (patch) | |
| tree | 31a5bc93de8c3a49442fa5db0652e6af7c2e54fc | |
| parent | e72b9da08319f6f4f86b0c93499cd522062c5e7b (diff) | |
| download | linux-1ea12fef83c3269eb7ba04f1d20db00c581515b2.tar.gz | |
staging: dgap: fix overflows and format strings
The boot message buffer could potentially overflow the stack and the heap. Additionally make sure format strings could not leak into printk() calls. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/dgap/dgap_driver.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/drivers/staging/dgap/dgap_driver.c b/drivers/staging/dgap/dgap_driver.c index 724a685753dd..40ef785a0428 100644 --- a/drivers/staging/dgap/dgap_driver.c +++ b/drivers/staging/dgap/dgap_driver.c @@ -474,7 +474,7 @@ static void dgap_cleanup_board(struct board_t *brd) DGAP_LOCK(dgap_global_lock, flags); brd->msgbuf = NULL; - printk(brd->msgbuf_head); + printk("%s", brd->msgbuf_head); kfree(brd->msgbuf_head); brd->msgbuf_head = NULL; DGAP_UNLOCK(dgap_global_lock, flags); @@ -628,7 +628,7 @@ static int dgap_found_board(struct pci_dev *pdev, int id) DPR_INIT(("dgap_scan(%d) - printing out the msgbuf\n", i)); DGAP_LOCK(dgap_global_lock, flags); brd->msgbuf = NULL; - printk(brd->msgbuf_head); + printk("%s", brd->msgbuf_head); kfree(brd->msgbuf_head); brd->msgbuf_head = NULL; DGAP_UNLOCK(dgap_global_lock, flags); @@ -955,25 +955,28 @@ static void dgap_mbuf(struct board_t *brd, const char *fmt, ...) { char buf[1024]; int i; unsigned long flags; + size_t length; DGAP_LOCK(dgap_global_lock, flags); /* Format buf using fmt and arguments contained in ap. */ va_start(ap, fmt); - i = vsprintf(buf, fmt, ap); + i = vsnprintf(buf, sizeof(buf), fmt, ap); va_end(ap); DPR((buf)); if (!brd || !brd->msgbuf) { - printk(buf); + printk("%s", buf); DGAP_UNLOCK(dgap_global_lock, flags); return; } - memcpy(brd->msgbuf, buf, strlen(buf)); - brd->msgbuf += strlen(buf); - *brd->msgbuf = 0; + length = strlen(buf) + 1; + if (brd->msgbuf - brd->msgbuf_head < length) + length = brd->msgbuf - brd->msgbuf_head; + memcpy(brd->msgbuf, buf, length); + brd->msgbuf += length; DGAP_UNLOCK(dgap_global_lock, flags); } |