[PATCH RFC 2/5] Revert "ubifs: Fix out-of-bounds memory access caused by abnormal value of node_len"

From: Zhihao Cheng
Date: Tue Jun 16 2020 - 03:10:55 EST


This reverts commit acc5af3efa303d5f36cc8c0f61716161f6ca1384.

No need to avoid memory oob in dumping for data node alone. Later, node
length will be passed into function 'ubifs_dump_node()' which replaces
all node dumping places.

Signed-off-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx>
---
fs/ubifs/io.c | 16 ++--------------
1 file changed, 2 insertions(+), 14 deletions(-)

diff --git a/fs/ubifs/io.c b/fs/ubifs/io.c
index 7e4bfaf2871f..8ceb51478800 100644
--- a/fs/ubifs/io.c
+++ b/fs/ubifs/io.c
@@ -225,7 +225,7 @@ int ubifs_is_mapped(const struct ubifs_info *c, int lnum)
int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum,
int offs, int quiet, int must_chk_crc)
{
- int err = -EINVAL, type, node_len, dump_node = 1;
+ int err = -EINVAL, type, node_len;
uint32_t crc, node_crc, magic;
const struct ubifs_ch *ch = buf;

@@ -278,22 +278,10 @@ int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum,
out_len:
if (!quiet)
ubifs_err(c, "bad node length %d", node_len);
- if (type == UBIFS_DATA_NODE && node_len > UBIFS_DATA_NODE_SZ)
- dump_node = 0;
out:
if (!quiet) {
ubifs_err(c, "bad node at LEB %d:%d", lnum, offs);
- if (dump_node) {
- ubifs_dump_node(c, buf);
- } else {
- int safe_len = min3(node_len, c->leb_size - offs,
- (int)UBIFS_MAX_DATA_NODE_SZ);
- pr_err("\tprevent out-of-bounds memory access\n");
- pr_err("\ttruncated data node length %d\n", safe_len);
- pr_err("\tcorrupted data node:\n");
- print_hex_dump(KERN_ERR, "\t", DUMP_PREFIX_OFFSET, 32, 1,
- buf, safe_len, 0);
- }
+ ubifs_dump_node(c, buf);
dump_stack();
}
return err;
--
2.25.4