Commit f59ff666 authored Jun 04, 2023 by Matthew Wilcox Committed by Greg Kroah-Hartman Sep 23, 2023

reiserfs: Check the return value from __getblk()



[ Upstream commit ba38980add7ffc9e674ada5b4ded4e7d14e76581 ]

__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: 1da177e4 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent e74903b5

fs/reiserfs/journal.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -2327,7 +2327,7 @@ 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) {
		@@ -2337,6 +2337,8 @@ 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;