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| author | Dan Carpenter <dan.carpenter@oracle.com> | 2021-11-05 13:45:12 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-11-06 13:30:43 -0700 |
| commit | a88e03cf3d190cf46bc4063a9b7efe87590de5f4 (patch) | |
| tree | 1ebbdecc2f00893fbcdfc066c0bedf04731265bc /drivers | |
| parent | 4aabdc14c4d2a01c2968bdc8919f81d9f9b4f790 (diff) | |
| download | lwn-a88e03cf3d190cf46bc4063a9b7efe87590de5f4.tar.gz lwn-a88e03cf3d190cf46bc4063a9b7efe87590de5f4.zip | |
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@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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/block/zram/zram_drv.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 081e77d595d7..f61910c65f0f 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -910,7 +910,7 @@ 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; } |