From: Andrew Goodbody <andrew.goodbody@linaro.org>
Date: Fri, 4 Jul 2025 10:53:18 +0000 (+0100)
Subject: fs: erofs: Do NULL check before dereferencing pointer
X-Git-Tag: v2025.10-rc1~88
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ff8a41ce4947c6d7f1826990d5d7b96d30928e3f;p=thirdparty%2Fu-boot.git

fs: erofs: Do NULL check before dereferencing pointer

The assignments to sect and off use the pointer from ctxt.cur_dev but
that has not been NULL checked before this is done. So instead move the
assignments after the NULL check.

This issue found by Smatch

Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>
Reviewed-by: Gao Xiang <xiang@kernel.org>
---

diff --git a/fs/erofs/fs.c b/fs/erofs/fs.c
index dcdc883e34c..db86928511e 100644
--- a/fs/erofs/fs.c
+++ b/fs/erofs/fs.c
@@ -11,12 +11,15 @@ static struct erofs_ctxt {
 
 int erofs_dev_read(int device_id, void *buf, u64 offset, size_t len)
 {
-	lbaint_t sect = offset >> ctxt.cur_dev->log2blksz;
-	int off = offset & (ctxt.cur_dev->blksz - 1);
+	lbaint_t sect;
+	int off;
 
 	if (!ctxt.cur_dev)
 		return -EIO;
 
+	sect = offset >> ctxt.cur_dev->log2blksz;
+	off = offset & (ctxt.cur_dev->blksz - 1);
+
 	if (fs_devread(ctxt.cur_dev, &ctxt.cur_part_info, sect,
 		       off, len, buf))
 		return 0;