diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2014-11-16 11:00:42 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-11-16 11:00:42 -0800
commit3b91270a0a2fe00b7aa1ce16b3ecf055315c64e3 (patch)
parent5f01feb8b97a4d65caa1456cb12f0f770497347f (diff)
x86-64: make csum_partial_copy_from_user() error handling consistent
Al Viro pointed out that the x86-64 csum_partial_copy_from_user() is somewhat confused about what it should do on errors, notably it mostly clears the uncopied end result buffer, but misses that for the initial alignment case. All users should check for errors, so it's dubious whether the clearing is even necessary, and Al also points out that we should probably clean up the calling conventions, but regardless of any future changes to this function, the fact that it is inconsistent is just annoying. So make the __get_user() failure path use the same error exit as all the other errors do. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Cc: David Miller <davem@davemloft.net> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/x86/lib/csum-wrappers_64.c b/arch/x86/lib/csum-wrappers_64.c
index 7609e0e421ec..1318f75d56e4 100644
--- a/arch/x86/lib/csum-wrappers_64.c
+++ b/arch/x86/lib/csum-wrappers_64.c
@@ -41,9 +41,8 @@ csum_partial_copy_from_user(const void __user *src, void *dst,
while (((unsigned long)src & 6) && len >= 2) {
__u16 val16;
- *errp = __get_user(val16, (const __u16 __user *)src);
- if (*errp)
- return isum;
+ if (__get_user(val16, (const __u16 __user *)src))
+ goto out_err;
*(__u16 *)dst = val16;
isum = (__force __wsum)add32_with_carry(

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