The patch titled
Subject: zram: off by one in read_block_state()
has been added to the -mm tree. Its filename is
zram-off-by-one-in-read_block_state.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/zram-off-by-one-in-read_block_state.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/zram-off-by-one-in-read_block_state.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Subject: zram: off by one in read_block_state()
snprintf() returns the number of bytes it would have printed if there were
space. But it does not count the NUL terminator. So that means that if
"count == copied" then this has already overflowed by one character.
This bug likely isn't super harmful in real life.
Link: https://lkml.kernel.org/r/20210916130404.GA25094@kili
Fixes: c0265342bff4 ("zram: introduce zram memory tracking")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/block/zram/zram_drv.c~zram-off-by-one-in-read_block_state
+++ a/drivers/block/zram/zram_drv.c
@@ -910,7 +910,7 @@ static ssize_t read_block_state(struct f
zram_test_flag(zram, index, ZRAM_HUGE) ? 'h' : '.',
zram_test_flag(zram, index, ZRAM_IDLE) ? 'i' : '.');
- if (count < copied) {
+ if (count <= copied) {
zram_slot_unlock(zram, index);
break;
}
_
Patches currently in -mm which might be from dan.carpenter@xxxxxxxxxx are
zram-off-by-one-in-read_block_state.patch
