| From aa8b82c64d4e5f582696e257a3f099382228fbf2 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 5 Nov 2021 13:45:12 -0700 |
| Subject: zram: off by one in read_block_state() |
| |
| From: Dan Carpenter <dan.carpenter@oracle.com> |
| |
| [ Upstream commit a88e03cf3d190cf46bc4063a9b7efe87590de5f4 ] |
| |
| 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@oracle.com> |
| Cc: Minchan Kim <minchan@kernel.org> |
| Cc: Sergey Senozhatsky <senozhatsky@chromium.org> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/block/zram/zram_drv.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c |
| index 719c6b7741afa..1cc9b67e9bcaa 100644 |
| --- a/drivers/block/zram/zram_drv.c |
| +++ b/drivers/block/zram/zram_drv.c |
| @@ -901,7 +901,7 @@ static ssize_t read_block_state(struct file *file, char __user *buf, |
| 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; |
| } |
| -- |
| 2.33.0 |
| |
