From: Serge Semin Date: Wed, 6 Dec 2017 14:31:54 +0000 (+0300) Subject: NTB: Fix UB/bug in ntb_mw_get_align() X-Git-Tag: v4.16-rc1~75^2~17 X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=f1678a4c66a5c2cb43f744f7dc7e048d59690166;p=linux.git NTB: Fix UB/bug in ntb_mw_get_align() Simple (1 << pidx) operation causes undefined behaviour when pidx >= 32. It must be casted to u64 to match the actual return value of ntb_link_is_up() method, so to have all the possible peer indexes covered and to get rid of undefined behaviour. Additionally there are special macros in "linux/bitops.h" to perform the bit-set-shift operations, so it's recommended to have them used for proper bit setting. Signed-off-by: Serge Semin Reviewed-by: Logan Gunthorpe Signed-off-by: Jon Mason --- diff --git a/include/linux/ntb.h b/include/linux/ntb.h index 21b1826a0953..181d16601dd9 100644 --- a/include/linux/ntb.h +++ b/include/linux/ntb.h @@ -767,7 +767,7 @@ static inline int ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int widx, resource_size_t *size_align, resource_size_t *size_max) { - if (!(ntb_link_is_up(ntb, NULL, NULL) & (1 << pidx))) + if (!(ntb_link_is_up(ntb, NULL, NULL) & BIT_ULL(pidx))) return -ENOTCONN; return ntb->ops->mw_get_align(ntb, pidx, widx, addr_align, size_align,