__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@xxxxxxxxxxxxx> Link: https://lore.kernel.org/lkml/CAFcO6XOacq3hscbXevPQP7sXRoYFz34ZdKPYjmd6k5sZuhGFDw@xxxxxxxxxxxxxx/ Tested-by: butt3rflyh4ck <butterflyhuangxx@xxxxxxxxx> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") # probably introduced in 2002 --- 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 4d11d60f493c..dd58e0dca5e5 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; -- 2.39.2
