Adding fix for one more place where the same error can occur
xfstest generic/525 can generate the following warning:
UBSAN: signed-integer-overflow in fs/cifs/file.c:2644:31
9223372036854775807 + 511 cannot be represented in type 'long long int'
Call Trace:
dump_stack+0x8d/0xb5
ubsan_epilogue+0x5/0x50
handle_overflow+0xa3/0xb0
cifs_write_end+0x424/0x440 [cifs]
generic_perform_write+0xef/0x190
due to overflowing loff_t (a signed 64 bit) when it is rounded up
to calculate number of 512 byte blocks in a file in two places.
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/cifs/file.c | 3 ++-
fs/cifs/inode.c | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 0166f39f1888..3cc17871471a 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2641,7 +2641,8 @@ static int cifs_write_end(struct file *file,
struct address_space *mapping,
spin_lock(&inode->i_lock);
if (pos > inode->i_size) {
i_size_write(inode, pos);
- inode->i_blocks = (512 - 1 + pos) >> 9;
+ /* round up to block boundary, avoid overflow loff_t */
+ inode->i_blocks = ((__u64)pos + (512 - 1)) >> 9;
}
spin_unlock(&inode->i_lock);
}
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 65f8a70cece3..f1dbcbc79abb 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -2631,7 +2631,7 @@ cifs_set_file_size(struct inode *inode, struct
iattr *attrs,
* this is best estimate we have for blocks allocated for a file
* Number of blocks must be rounded up so size 1 is not 0 blocks
*/
- inode->i_blocks = (512 - 1 + attrs->ia_size) >> 9;
+ inode->i_blocks = ((__u64)attrs->ia_size + (512 - 1)) >> 9;
/*
* The man page of truncate says if the size changed,
--
Thanks,
Steve
