From: Jan Kara jack@suse.cz
stable inclusion from stable-5.10.50 commit b368b0375e776b21c3cc42a1a4680f3ca6823224 bugzilla: 174522 https://gitee.com/openeuler/kernel/issues/I4DNFY
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit d0b040f5f2557b2f507c01e88ad8cff424fdc6a9 upstream.
A code in iomap alloc may overflow block number when converting it to byte offset. Luckily this is mostly harmless as we will just use more expensive method of writing using unwritten extents even though we are writing beyond i_size.
Cc: stable@kernel.org Fixes: 378f32bab371 ("ext4: introduce direct I/O write using iomap infrastructure") Signed-off-by: Jan Kara jack@suse.cz Link: https://lore.kernel.org/r/20210412102333.2676-4-jack@suse.cz Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com --- fs/ext4/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 63b53660dc5b..0207579d7e04 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3422,7 +3422,7 @@ static int ext4_iomap_alloc(struct inode *inode, struct ext4_map_blocks *map, * i_disksize out to i_size. This could be beyond where direct I/O is * happening and thus expose allocated blocks to direct I/O reads. */ - else if ((map->m_lblk * (1 << blkbits)) >= i_size_read(inode)) + else if (((loff_t)map->m_lblk << blkbits) >= i_size_read(inode)) m_flags = EXT4_GET_BLOCKS_CREATE; else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) m_flags = EXT4_GET_BLOCKS_IO_CREATE_EXT;