From: Nikita Zhandarovich <n.zhandarovich@fintech.ru> stable inclusion from stable-v6.6.78 commit f2bd0f1ab47822fe5bd699c8458b896c4b2edea1 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBPC8Z CVE: CVE-2025-21736 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- 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@gmail.com Fixes: 622daaff0a89 ("nilfs2: fiemap support") Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru> Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com> --- fs/nilfs2/inode.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index 489592644b68..5f2d73f36e0d 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -1267,7 +1267,7 @@ int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 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( @@ -1280,14 +1280,14 @@ int nilfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, 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; } -- 2.25.1