This is a note to let you know that I've just added the patch titled frv: fix clear_user() to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: frv-fix-clear_user.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 3b8767a8f00cc6538ba6b1cf0f88502e2fd2eb90 Mon Sep 17 00:00:00 2001 From: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Date: Thu, 18 Aug 2016 20:54:02 -0400 Subject: frv: fix clear_user() From: Al Viro <viro@xxxxxxxxxxxxxxxxxx> commit 3b8767a8f00cc6538ba6b1cf0f88502e2fd2eb90 upstream. It should check access_ok(). Otherwise a bunch of places turn into trivially exploitable rootholes. Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/frv/include/asm/uaccess.h | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/arch/frv/include/asm/uaccess.h +++ b/arch/frv/include/asm/uaccess.h @@ -263,19 +263,25 @@ do { \ extern long __memset_user(void *dst, unsigned long count); extern long __memcpy_user(void *dst, const void *src, unsigned long count); -#define clear_user(dst,count) __memset_user(____force(dst), (count)) +#define __clear_user(dst,count) __memset_user(____force(dst), (count)) #define __copy_from_user_inatomic(to, from, n) __memcpy_user((to), ____force(from), (n)) #define __copy_to_user_inatomic(to, from, n) __memcpy_user(____force(to), (from), (n)) #else -#define clear_user(dst,count) (memset(____force(dst), 0, (count)), 0) +#define __clear_user(dst,count) (memset(____force(dst), 0, (count)), 0) #define __copy_from_user_inatomic(to, from, n) (memcpy((to), ____force(from), (n)), 0) #define __copy_to_user_inatomic(to, from, n) (memcpy(____force(to), (from), (n)), 0) #endif -#define __clear_user clear_user +static inline unsigned long __must_check +clear_user(void __user *to, unsigned long n) +{ + if (likely(__access_ok(to, n))) + n = __clear_user(to, n); + return n; +} static inline unsigned long __must_check __copy_to_user(void __user *to, const void *from, unsigned long n) Patches currently in stable-queue which might be from viro@xxxxxxxxxxxxxxxxxx are queue-4.4/nios2-copy_from_user-should-zero-the-tail-of-destination.patch queue-4.4/m32r-fix-__get_user.patch queue-4.4/microblaze-fix-copy_from_user.patch queue-4.4/cris-buggered-copy_from_user-copy_to_user-clear_user.patch queue-4.4/asm-generic-make-copy_from_user-zero-the-destination-properly.patch queue-4.4/metag-copy_from_user-should-zero-the-destination-on-access_ok-failure.patch queue-4.4/score-fix-__get_user-get_user.patch queue-4.4/parisc-fix-copy_from_user.patch queue-4.4/mips-copy_from_user-must-zero-the-destination-on-access_ok-failure.patch queue-4.4/alpha-fix-copy_from_user.patch queue-4.4/mn10300-failing-__get_user-and-get_user-should-zero.patch queue-4.4/openrisc-fix-copy_from_user.patch queue-4.4/avr32-fix-copy_from_user.patch queue-4.4/score-fix-copy_from_user-and-friends.patch queue-4.4/sh64-failing-__get_user-should-zero.patch queue-4.4/arc-uaccess-get_user-to-zero-out-dest-in-cause-of-fault.patch queue-4.4/hexagon-fix-strncpy_from_user-error-return.patch queue-4.4/frv-fix-clear_user.patch queue-4.4/fix-minor-infoleak-in-get_user_ex.patch queue-4.4/asm-generic-make-get_user-clear-the-destination-on-errors.patch queue-4.4/mn10300-copy_from_user-should-zero-on-access_ok-failure.patch queue-4.4/s390-get_user-should-zero-on-failure.patch queue-4.4/microblaze-fix-__get_user.patch queue-4.4/blackfin-fix-copy_from_user.patch queue-4.4/fix-iov_iter_fault_in_readable.patch queue-4.4/nios2-fix-__get_user.patch queue-4.4/sh-fix-copy_from_user.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html