From ba38980add7ffc9e674ada5b4ded4e7d14e76581 Mon Sep 17 00:00:00 2001
From: Matthew Wilcox <willy@infradead.org>
Date: Sun, 4 Jun 2023 12:16:06 +0100
Subject: [PATCH] reiserfs: Check the return value from __getblk()
Git-commit: ba38980add7ffc9e674ada5b4ded4e7d14e76581
Patch-mainline: v6.6-rc1
References: git-fixes
__getblk() can return a NULL pointer if we run out of memory or if we
try to access beyond the end of the device; check it and handle it
appropriately.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/lkml/CAFcO6XOacq3hscbXevPQP7sXRoYFz34ZdKPYjmd6k5sZuhGFDw@mail.gmail.com/
Tested-by: butt3rflyh4ck <butterflyhuangxx@gmail.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") # probably introduced in 2002
Acked-by: Edward Shishkin <edward.shishkin@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Acked-by: Anthony Iliopoulos <ailiop@suse.com>
---
fs/reiserfs/journal.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/reiserfs/journal.c b/fs/reiserfs/journal.c
index 479aa4a57602..015bfe4e4524 100644
--- a/fs/reiserfs/journal.c
+++ b/fs/reiserfs/journal.c
@@ -2326,7 +2326,7 @@ static struct buffer_head *reiserfs_breada(struct block_device *dev,
int i, j;
bh = __getblk(dev, block, bufsize);
- if (buffer_uptodate(bh))
+ if (!bh || buffer_uptodate(bh))
return (bh);
if (block + BUFNR > max_block) {
@@ -2336,6 +2336,8 @@ static struct buffer_head *reiserfs_breada(struct block_device *dev,
j = 1;
for (i = 1; i < blocks; i++) {
bh = __getblk(dev, block + i, bufsize);
+ if (!bh)
+ break;
if (buffer_uptodate(bh)) {
brelse(bh);
break;
--
2.43.0