This is a note to let you know that I've just added the patch titled zsmalloc: expand class bit to the 4.9-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: zsmalloc-expand-class-bit.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 85d492f28d056c40629fc25d79f54da618a29dc4 Mon Sep 17 00:00:00 2001 From: Minchan Kim <minchan@xxxxxxxxxx> Date: Thu, 13 Apr 2017 14:56:40 -0700 Subject: zsmalloc: expand class bit From: Minchan Kim <minchan@xxxxxxxxxx> commit 85d492f28d056c40629fc25d79f54da618a29dc4 upstream. Now 64K page system, zsamlloc has 257 classes so 8 class bit is not enough. With that, it corrupts the system when zsmalloc stores 65536byte data(ie, index number 256) so that this patch increases class bit for simple fix for stable backport. We should clean up this mess soon. index size 0 32 1 288 .. .. 204 52256 256 65536 Fixes: 3783689a1 ("zsmalloc: introduce zspage structure") Link: http://lkml.kernel.org/r/1492042622-12074-3-git-send-email-minchan@xxxxxxxxxx Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx> Cc: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- mm/zsmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -280,7 +280,7 @@ struct zs_pool { struct zspage { struct { unsigned int fullness:FULLNESS_BITS; - unsigned int class:CLASS_BITS; + unsigned int class:CLASS_BITS + 1; unsigned int isolated:ISOLATED_BITS; unsigned int magic:MAGIC_VAL_BITS; }; Patches currently in stable-queue which might be from minchan@xxxxxxxxxx are queue-4.9/zram-do-not-use-copy_page-with-non-page-aligned-address.patch queue-4.9/zram-fix-operator-precedence-to-get-offset.patch queue-4.9/thp-fix-madv_dontneed-vs.-madv_free-race.patch queue-4.9/zsmalloc-expand-class-bit.patch