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authorYun Zhou <yun.zhou@windriver.com>2021-06-26 11:21:55 +0800
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2021-06-26 09:18:48 -0400
commitd3b16034a24a112bb83aeb669ac5b9b01f744bb7 (patch)
tree8c3c57156010b8455fe76226777e3ed77b1a130b /lib
parentc8895e271f7994a3ecb13b8a280e39aa53879545 (diff)
seq_buf: Fix overflow in seq_buf_putmem_hex()
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@oasis.local.home/ Link: https://lkml.kernel.org/r/20210626032156.47889-1-yun.zhou@windriver.com Cc: stable@vger.kernel.org Fixes: 5e3ca0ec76fce ("ftrace: introduce the "hex" output method") Signed-off-by: Yun Zhou <yun.zhou@windriver.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/seq_buf.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/lib/seq_buf.c b/lib/seq_buf.c
index 707453f5d58e..62c20596ef42 100644
--- a/lib/seq_buf.c
+++ b/lib/seq_buf.c
@@ -229,8 +229,10 @@ int seq_buf_putmem_hex(struct seq_buf *s, const void *mem,
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