From: Nikita Zhandarovich <n.zhandarovich@xxxxxxxxxx> commit 6438ef381c183444f7f9d1de18f22661cba1e946 upstream. Since nilfs_bmap_lookup_contig() in nilfs_fiemap() calculates its result by being prepared to go through potentially maxblocks == INT_MAX blocks, the value in n may experience an overflow caused by left shift of blkbits. While it is extremely unlikely to occur, play it safe and cast right hand expression to wider type to mitigate the issue. Found by Linux Verification Center (linuxtesting.org) with static analysis tool SVACE. Link: https://lkml.kernel.org/r/20250124222133.5323-1-konishi.ryusuke@xxxxxxxxx Fixes: 622daaff0a89 ("nilfs2: fiemap support") Signed-off-by: Nikita Zhandarovich <n.zhandarovich@xxxxxxxxxx> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/nilfs2/inode.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -1188,7 +1188,7 @@ int nilfs_fiemap(struct inode *inode, st if (size) { if (phys && blkphy << blkbits == phys + size) { /* The current extent goes on */ - size += n << blkbits; + size += (u64)n << blkbits; } else { /* Terminate the current extent */ ret = fiemap_fill_next_extent( @@ -1201,14 +1201,14 @@ int nilfs_fiemap(struct inode *inode, st flags = FIEMAP_EXTENT_MERGED; logical = blkoff << blkbits; phys = blkphy << blkbits; - size = n << blkbits; + size = (u64)n << blkbits; } } else { /* Start a new extent */ flags = FIEMAP_EXTENT_MERGED; logical = blkoff << blkbits; phys = blkphy << blkbits; - size = n << blkbits; + size = (u64)n << blkbits; } blkoff += n; } Patches currently in stable-queue which might be from n.zhandarovich@xxxxxxxxxx are queue-6.13/nilfs2-fix-possible-int-overflows-in-nilfs_fiemap.patch
