From 8c505ebeed8045b488b2e60b516c752b851f8437 Mon Sep 17 00:00:00 2001
From: Artem Sadovnikov <ancowi69@gmail.com>
Date: Sat, 5 Oct 2024 10:06:57 +0000
Subject: [PATCH] jfs: xattr: check invalid xattr size more strictly
commit d9f9d96136cba8fedd647d2c024342ce090133c2 upstream.
Commit 7c55b78818cf ("jfs: xattr: fix buffer overflow for invalid xattr")
also addresses this issue but it only fixes it for positive values, while
ea_size is an integer type and can take negative values, e.g. in case of
a corrupted filesystem. This still breaks validation and would overflow
because of implicit conversion from int to size_t in print_hex_dump().
Fix this issue by clamping the ea_size value instead.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Cc: stable@vger.kernel.org
Signed-off-by: Artem Sadovnikov <ancowi69@gmail.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/jfs/xattr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/jfs/xattr.c b/fs/jfs/xattr.c
index 0fb05e314edf6..24afbae87225a 100644
--- a/fs/jfs/xattr.c
+++ b/fs/jfs/xattr.c
@@ -559,7 +559,7 @@ static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size)
size_check:
if (EALIST_SIZE(ea_buf->xattr) != ea_size) {
- int size = min_t(int, EALIST_SIZE(ea_buf->xattr), ea_size);
+ int size = clamp_t(int, ea_size, 0, EALIST_SIZE(ea_buf->xattr));
printk(KERN_ERR "ea_get: invalid extended attribute\n");
print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1,
--
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