+ kexec-return-efault-on-copy_to_user-failures.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     kexec: return -EFAULT on copy_to_user() failures
has been added to the -mm tree.  Its filename is
     kexec-return-efault-on-copy_to_user-failures.patch

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------------------------------------------------------
Subject: kexec: return -EFAULT on copy_to_user() failures
From: Dan Carpenter <error27@gmail.com>

copy_to/from_user() returns the number of bytes remaining to be copied. 
It never returns a negative value.  The correct return code is -EFAULT and
not -EIO.

All the callers check for non-zero returns so that's Ok, but the return
code is passed to the user so we should fix this.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Simon Kagstrom <simon.kagstrom@netinsight.net>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/kexec.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff -puN kernel/kexec.c~kexec-return-efault-on-copy_to_user-failures kernel/kexec.c
--- a/kernel/kexec.c~kexec-return-efault-on-copy_to_user-failures
+++ a/kernel/kexec.c
@@ -151,8 +151,10 @@ static int do_kimage_alloc(struct kimage
 	image->nr_segments = nr_segments;
 	segment_bytes = nr_segments * sizeof(*segments);
 	result = copy_from_user(image->segment, segments, segment_bytes);
-	if (result)
+	if (result) {
+		result = -EFAULT;
 		goto out;
+	}
 
 	/*
 	 * Verify we have good destination addresses.  The caller is
@@ -827,7 +829,7 @@ static int kimage_load_normal_segment(st
 		result = copy_from_user(ptr, buf, uchunk);
 		kunmap(page);
 		if (result) {
-			result = (result < 0) ? result : -EIO;
+			result = -EFAULT;
 			goto out;
 		}
 		ubytes -= uchunk;
@@ -882,7 +884,7 @@ static int kimage_load_crash_segment(str
 		kexec_flush_icache_page(page);
 		kunmap(page);
 		if (result) {
-			result = (result < 0) ? result : -EIO;
+			result = -EFAULT;
 			goto out;
 		}
 		ubytes -= uchunk;
_

Patches currently in -mm which might be from error27@gmail.com are

linux-next.patch
mtd-sst25l-check-for-null-consistently.patch
scsi-remove-superfluous-null-pointer-check-from-scsi_kill_request.patch
autofs4-remove-unneeded-null-check-in-try_to_fill_dentry.patch
cgroups-save-space-for-the-terminator.patch
kexec-return-efault-on-copy_to_user-failures.patch