[PATCH][next] afs: fix integer overflow when shifting 1 more than 32 places

From: Colin King
Date: Wed Apr 11 2018 - 09:26:24 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Shifting 1 (a 32 bit signed int) more than 32 places will overflow
the int, so explicitly use 1ULL to avoid this overflow.

Detected by CoverityScan, CID#1467808 ("Uninitentional integer overflow")

Fixes: 63a4681ff39c ("afs: Locally edit directory data for mkdir/create/unlink/...")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
fs/afs/dir_edit.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/afs/dir_edit.c b/fs/afs/dir_edit.c
index 8b400f5aead5..42a63f9467c5 100644
--- a/fs/afs/dir_edit.c
+++ b/fs/afs/dir_edit.c
@@ -40,7 +40,7 @@ static int afs_find_contig_bits(union afs_xdr_dir_block *block, unsigned int nr_
bitmap |= (u64)block->hdr.bitmap[7] << 7 * 8;
bitmap >>= 1; /* The first entry is metadata */
bit = 1;
- mask = (1 << nr_slots) - 1;
+ mask = (1ULL << nr_slots) - 1;

do {
if (sizeof(unsigned long) == 8)
@@ -74,7 +74,7 @@ static void afs_set_contig_bits(union afs_xdr_dir_block *block,
{
u64 mask, before, after;

- mask = (1 << nr_slots) - 1;
+ mask = (1ULL << nr_slots) - 1;
mask <<= bit;

before = *(u64 *)block->hdr.bitmap;
@@ -99,7 +99,7 @@ static void afs_clear_contig_bits(union afs_xdr_dir_block *block,
{
u64 mask, before, after;

- mask = (1 << nr_slots) - 1;
+ mask = (1ULL << nr_slots) - 1;
mask <<= bit;

before = *(u64 *)block->hdr.bitmap;
--
2.17.0