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| author | Yun Zhou <yun.zhou@windriver.com> | 2021-06-26 11:21:55 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-19 08:53:16 +0200 |
| commit | 33ab9138a13e379cf1c4ccd76b97ae2ee8c5421b (patch) | |
| tree | 6e9e702a4915ec1b582cff1162add0720930c794 | |
| parent | 854bf719660176592ba3eef4dd63f54b08f311ef (diff) | |
| download | linux-stable-33ab9138a13e379cf1c4ccd76b97ae2ee8c5421b.tar.gz linux-stable-33ab9138a13e379cf1c4ccd76b97ae2ee8c5421b.tar.bz2 linux-stable-33ab9138a13e379cf1c4ccd76b97ae2ee8c5421b.zip | |
seq_buf: Fix overflow in seq_buf_putmem_hex()
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@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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | lib/seq_buf.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/lib/seq_buf.c b/lib/seq_buf.c index b15dbb6f061a..5dd4d1d02a17 100644 --- a/lib/seq_buf.c +++ b/lib/seq_buf.c @@ -228,8 +228,10 @@ 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 |