[PATCH openEuler-1.0-LTS 1/2] Input: joydev - prevent potential read overflow in ioctl
From: Dan Carpenter <dan.carpenter@oracle.com> stable inclusion from linux-4.19.178 commit 88438fdeeffe11dcb05c2dd0ddd22cb6e3f024b4 CVE: CVE-2021-3612 -------------------------------- commit 182d679b2298d62bf42bb14b12a8067b8e17b617 upstream. The problem here is that "len" might be less than "joydev->nabs" so the loops which verfy abspam[i] and keypam[] might read beyond the buffer. Fixes: 999b874f4aa3 ("Input: joydev - validate axis/button maps before clobbering current ones") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/YCyzR8WvFRw4HWw6@mwanda [dtor: additional check for len being even in joydev_handle_JSIOCSBTNMAP] Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/input/joydev.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/input/joydev.c b/drivers/input/joydev.c index 4c1e427dfabb9..7ef6e1c165e35 100644 --- a/drivers/input/joydev.c +++ b/drivers/input/joydev.c @@ -460,7 +460,7 @@ static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev, if (IS_ERR(abspam)) return PTR_ERR(abspam); - for (i = 0; i < joydev->nabs; i++) { + for (i = 0; i < len && i < joydev->nabs; i++) { if (abspam[i] > ABS_MAX) { retval = -EINVAL; goto out; @@ -484,6 +484,9 @@ static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev, int i; int retval = 0; + if (len % sizeof(*keypam)) + return -EINVAL; + len = min(len, sizeof(joydev->keypam)); /* Validate the map. */ @@ -491,7 +494,7 @@ static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev, if (IS_ERR(keypam)) return PTR_ERR(keypam); - for (i = 0; i < joydev->nkey; i++) { + for (i = 0; i < (len / 2) && i < joydev->nkey; i++) { if (keypam[i] > KEY_MAX || keypam[i] < BTN_MISC) { retval = -EINVAL; goto out; -- 2.25.1
From: Alexander Larkin <avlarkin82@gmail.com> stable inclusion from linux-4.19.198 commit b62ce8e3f7fbd81ea7c9341ac5e0d445f685f6af CVE: CVE-2021-3612 -------------------------------- commit f8f84af5da9ee04ef1d271528656dac42a090d00 upstream. Even though we validate user-provided inputs we then traverse past validated data when applying the new map. The issue was originally discovered by Murray McAllister with this simple POC (if the following is executed by an unprivileged user it will instantly panic the system): int main(void) { int fd, ret; unsigned int buffer[10000]; fd = open("/dev/input/js0", O_RDONLY); if (fd == -1) printf("Error opening file\n"); ret = ioctl(fd, JSIOCSBTNMAP & ~IOCSIZE_MASK, &buffer); printf("%d\n", ret); } The solution is to traverse internal buffer which is guaranteed to only contain valid date when constructing the map. Fixes: 182d679b2298 ("Input: joydev - prevent potential read overflow in ioctl") Fixes: 999b874f4aa3 ("Input: joydev - validate axis/button maps before clobbering current ones") Reported-by: Murray McAllister <murray.mcallister@gmail.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Alexander Larkin <avlarkin82@gmail.com> Link: https://lore.kernel.org/r/20210620120030.1513655-1-avlarkin82@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/input/joydev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/input/joydev.c b/drivers/input/joydev.c index 7ef6e1c165e35..9123799365e63 100644 --- a/drivers/input/joydev.c +++ b/drivers/input/joydev.c @@ -504,7 +504,7 @@ static int joydev_handle_JSIOCSBTNMAP(struct joydev *joydev, memcpy(joydev->keypam, keypam, len); for (i = 0; i < joydev->nkey; i++) - joydev->keymap[keypam[i] - BTN_MISC] = i; + joydev->keymap[joydev->keypam[i] - BTN_MISC] = i; out: kfree(keypam); -- 2.25.1
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Yang Yingliang