This is a note to let you know that I've just added the patch titled SUNRPC: Fix memory corruption issue on 32-bit highmem systems to the 3.10-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: sunrpc-fix-memory-corruption-issue-on-32-bit-highmem-systems.patch and it can be found in the queue-3.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 347e2233b7667e336d9f671f1a52dfa3f0416e2c Mon Sep 17 00:00:00 2001 From: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> Date: Wed, 28 Aug 2013 13:35:13 -0400 Subject: SUNRPC: Fix memory corruption issue on 32-bit highmem systems From: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> commit 347e2233b7667e336d9f671f1a52dfa3f0416e2c upstream. Some architectures, such as ARM-32 do not return the same base address when you call kmap_atomic() twice on the same page. This causes problems for the memmove() call in the XDR helper routine "_shift_data_right_pages()", since it defeats the detection of overlapping memory ranges, and has been seen to corrupt memory. The fix is to distinguish between the case where we're doing an inter-page copy or not. In the former case of we know that the memory ranges cannot possibly overlap, so we can additionally micro-optimise by replacing memmove() with memcpy(). Reported-by: Mark Young <MYoung@xxxxxxxxxx> Reported-by: Matt Craighead <mcraighead@xxxxxxxxxx> Cc: Bruce Fields <bfields@xxxxxxxxxxxx> Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx> Tested-by: Matt Craighead <mcraighead@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/sunrpc/xdr.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -207,10 +207,13 @@ _shift_data_right_pages(struct page **pa pgfrom_base -= copy; vto = kmap_atomic(*pgto); - vfrom = kmap_atomic(*pgfrom); - memmove(vto + pgto_base, vfrom + pgfrom_base, copy); + if (*pgto != *pgfrom) { + vfrom = kmap_atomic(*pgfrom); + memcpy(vto + pgto_base, vfrom + pgfrom_base, copy); + kunmap_atomic(vfrom); + } else + memmove(vto + pgto_base, vto + pgfrom_base, copy); flush_dcache_page(*pgto); - kunmap_atomic(vfrom); kunmap_atomic(vto); } while ((len -= copy) != 0); Patches currently in stable-queue which might be from Trond.Myklebust@xxxxxxxxxx are queue-3.10/sunrpc-fix-memory-corruption-issue-on-32-bit-highmem-systems.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