From 812cb21259ad024a9905e856d573b82413b569d1 Mon Sep 17 00:00:00 2001 From: Celeste Liu Date: Tue, 31 May 2022 15:56:52 +0800 Subject: [PATCH] riscv: mmap with PROT_WRITE but no PROT_READ is invalid [ Upstream commit 2139619bcad7ac44cc8f6f749089120594056613 ] As mentioned in Table 4.5 in RISC-V spec Volume 2 Section 4.3, write but not read is "Reserved for future use.". For now, they are not valid. In the current code, -wx is marked as invalid, but -w- is not marked as invalid. This patch refines that judgment. Reported-by: xctan Co-developed-by: dram Signed-off-by: dram Co-developed-by: Ruizhe Pan Signed-off-by: Ruizhe Pan Signed-off-by: Celeste Liu Link: https://lore.kernel.org/r/PH7PR14MB559464DBDD310E755F5B21E8CEDC9@PH7PR14MB5594.namprd14.prod.outlook.com Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin --- arch/riscv/kernel/sys_riscv.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c index 12f8a7fce78b..8a7880b9c433 100644 --- a/arch/riscv/kernel/sys_riscv.c +++ b/arch/riscv/kernel/sys_riscv.c @@ -18,9 +18,8 @@ static long riscv_sys_mmap(unsigned long addr, unsigned long len, if (unlikely(offset & (~PAGE_MASK >> page_shift_offset))) return -EINVAL; - if ((prot & PROT_WRITE) && (prot & PROT_EXEC)) - if (unlikely(!(prot & PROT_READ))) - return -EINVAL; + if (unlikely((prot & PROT_WRITE) && !(prot & PROT_READ))) + return -EINVAL; return ksys_mmap_pgoff(addr, len, prot, flags, fd, offset >> (PAGE_SHIFT - page_shift_offset));