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authorMikulas Patocka <mpatocka@redhat.com>2014-01-22 23:04:33 -0500
committerBen Hutchings <ben@decadent.org.uk>2014-04-02 00:58:47 +0100
commitb93b90ff7c50288d602108ae1a09673df3f799a8 (patch)
tree73a148e6e4a1c211e264cb78a005bb4760cde385 /arch/alpha
parente86e416d709499082625b6b8d3991813255c3779 (diff)
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alpha: fix broken network checksum
commit 0ef38d70d4118b2ce1a538d14357be5ff9dc2bbd upstream. The patch 3ddc5b46a8e90f3c9251338b60191d0a804b0d92 breaks networking on alpha (there is a follow-up fix 5cfe8f1ba5eebe6f4b6e5858cdb1a5be4f3272a6, but networking is still broken even with the second patch). The patch 3ddc5b46a8e90f3c9251338b60191d0a804b0d92 makes csum_partial_copy_from_user check the pointer with access_ok. However, csum_partial_copy_from_user is called also from csum_partial_copy_nocheck and csum_partial_copy_nocheck is called on kernel pointers and it is supposed not to check pointer validity. This bug results in ssh session hangs if the system is loaded and bulk data are printed to ssh terminal. This patch fixes csum_partial_copy_nocheck to call set_fs(KERNEL_DS), so that access_ok in csum_partial_copy_from_user accepts kernel-space addresses. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Matt Turner <mattst88@gmail.com> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch/alpha')
-rw-r--r--arch/alpha/lib/csum_partial_copy.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/alpha/lib/csum_partial_copy.c b/arch/alpha/lib/csum_partial_copy.c
index 40736da..1d2ef5a 100644
--- a/arch/alpha/lib/csum_partial_copy.c
+++ b/arch/alpha/lib/csum_partial_copy.c
@@ -373,6 +373,11 @@ csum_partial_copy_from_user(const void __user *src, void *dst, int len,
__wsum
csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
{
- return csum_partial_copy_from_user((__force const void __user *)src,
- dst, len, sum, NULL);
+ __wsum checksum;
+ mm_segment_t oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ checksum = csum_partial_copy_from_user((__force const void __user *)src,
+ dst, len, sum, NULL);
+ set_fs(oldfs);
+ return checksum;
}