hamza.kesraoui/sst-linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

iommufd/iova_bitmap: Fix shift-out-of-bounds in iova_bitmap_offset_to_index()

Browse Source 
[ Upstream commit e24c1551059268b37f6f40639883eafb281b8b9c ]

Resolve a UBSAN shift-out-of-bounds issue in iova_bitmap_offset_to_index()
where shifting the constant "1" (of type int) by bitmap->mapped.pgshift
(an unsigned long value) could result in undefined behavior.

The constant "1" defaults to a 32-bit "int", and when "pgshift" exceeds
31 (e.g., pgshift = 63) the shift operation overflows, as the result
cannot be represented in a 32-bit type.

To resolve this, the constant is updated to "1UL", promoting it to an
unsigned long type to match the operand's type.

Fixes: 58ccf0190d ("vfio: Add an IOVA bitmap support")
Link: https://patch.msgid.link/r/20250113223820.10713-1-qasdev00@gmail.com
Reported-by: syzbot <syzbot+85992ace37d5b7b51635@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=85992ace37d5b7b51635
Signed-off-by: Qasim Ijaz <qasdev00@gmail.com>
Reviewed-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Qasim Ijaz 2025-01-13 22:38:20 +00:00 committed by Greg Kroah-Hartman
parent 720653309d
commit 44d9c94b7a
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/vfio/iova_bitmap.c
View File

@ -126,7 +126,7 @@ struct iova_bitmap {
static unsigned long iova_bitmap_offset_to_index(struct iova_bitmap *bitmap,
unsigned long iova)
{
unsigned long pgsize = 1 << bitmap->mapped.pgshift;
unsigned long pgsize = 1UL << bitmap->mapped.pgshift;
return iova / (BITS_PER_TYPE(*bitmap->bitmap) * pgsize);
}