This is a note to let you know that I've just added the patch titled
seq_buf: Fix overflow in seq_buf_putmem_hex()
to the 5.13-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:
seq_buf-fix-overflow-in-seq_buf_putmem_hex.patch
and it can be found in the queue-5.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d3b16034a24a112bb83aeb669ac5b9b01f744bb7 Mon Sep 17 00:00:00 2001
From: Yun Zhou <yun.zhou@xxxxxxxxxxxxx>
Date: Sat, 26 Jun 2021 11:21:55 +0800
Subject: seq_buf: Fix overflow in seq_buf_putmem_hex()
From: Yun Zhou <yun.zhou@xxxxxxxxxxxxx>
commit d3b16034a24a112bb83aeb669ac5b9b01f744bb7 upstream.
There's two variables being increased in that loop (i and j), and i
follows the raw data, and j follows what is being written into the buffer.
We should compare 'i' to MAX_MEMHEX_BYTES or compare 'j' to HEX_CHARS.
Otherwise, if 'j' goes bigger than HEX_CHARS, it will overflow the
destination buffer.
Link: https://lore.kernel.org/lkml/20210625122453.5e2fe304@xxxxxxxxxxxxxxxx/
Link: https://lkml.kernel.org/r/20210626032156.47889-1-yun.zhou@xxxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 5e3ca0ec76fce ("ftrace: introduce the "hex" output method")
Signed-off-by: Yun Zhou <yun.zhou@xxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
lib/seq_buf.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/lib/seq_buf.c
+++ b/lib/seq_buf.c
@@ -229,8 +229,10 @@ int seq_buf_putmem_hex(struct seq_buf *s
WARN_ON(s->size == 0);
+ BUILD_BUG_ON(MAX_MEMHEX_BYTES * 2 >= HEX_CHARS);
+
while (len) {
- start_len = min(len, HEX_CHARS - 1);
+ start_len = min(len, MAX_MEMHEX_BYTES);
#ifdef __BIG_ENDIAN
for (i = 0, j = 0; i < start_len; i++) {
#else
Patches currently in stable-queue which might be from yun.zhou@xxxxxxxxxxxxx are
queue-5.13/seq_buf-fix-overflow-in-seq_buf_putmem_hex.patch
