6.4-stable review patch. If anyone has any objections, please let me know.
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From: Matthew Wilcox willy@infradead.org
[ 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/CAFcO6XOacq3hscbXevPQP7sXRoYFz34ZdKPYjmd6k5sZuh... 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 Signed-off-by: Sasha Levin sashal@kernel.org --- 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 4d11d60f493c1..dd58e0dca5e5a 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;