From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D92D87B for ; Wed, 23 Nov 2022 08:58:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EDF71C433C1; Wed, 23 Nov 2022 08:58:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669193911; bh=WH18cPsKWwF+LC7xjVD+TnfDBYhZyD/dORe/weZmqmA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D5CuJVRSS9Zi8ceWbrRFlwBS0jMdSLYeWWuJ/wvmDd9FXDvgMl0rqWa4coIIQNUeB Efep4myU9aXCgrJpOHWIuN/RLIcUtcNyKjX2eg087LUxek8T9fuk2E15YqR9ensEez QhPYpHIhmIpVBaEgjfFFeXVKdOL8PHzGPG5iNbLE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Gaosheng Cui , "Andrew G. Morgan" , Serge Hallyn , Paul Moore , Sasha Levin Subject: [PATCH 4.14 05/88] capabilities: fix undefined behavior in bit shift for CAP_TO_MASK Date: Wed, 23 Nov 2022 09:50:02 +0100 Message-Id: <20221123084548.726605289@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221123084548.535439312@linuxfoundation.org> References: <20221123084548.535439312@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Gaosheng Cui [ Upstream commit 46653972e3ea64f79e7f8ae3aa41a4d3fdb70a13 ] Shifting signed 32-bit value by 31 bits is undefined, so changing significant bit to unsigned. The UBSAN warning calltrace like below: UBSAN: shift-out-of-bounds in security/commoncap.c:1252:2 left shift of 1 by 31 places cannot be represented in type 'int' Call Trace: dump_stack_lvl+0x7d/0xa5 dump_stack+0x15/0x1b ubsan_epilogue+0xe/0x4e __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c cap_task_prctl+0x561/0x6f0 security_task_prctl+0x5a/0xb0 __x64_sys_prctl+0x61/0x8f0 do_syscall_64+0x58/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: e338d263a76a ("Add 64-bit capability support to the kernel") Signed-off-by: Gaosheng Cui Acked-by: Andrew G. Morgan Reviewed-by: Serge Hallyn Signed-off-by: Paul Moore Signed-off-by: Sasha Levin --- include/uapi/linux/capability.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/uapi/linux/capability.h b/include/uapi/linux/capability.h index 240fdb9a60f6..6e0d68e841cd 100644 --- a/include/uapi/linux/capability.h +++ b/include/uapi/linux/capability.h @@ -376,7 +376,7 @@ struct vfs_ns_cap_data { */ #define CAP_TO_INDEX(x) ((x) >> 5) /* 1 << 5 == bits in __u32 */ -#define CAP_TO_MASK(x) (1 << ((x) & 31)) /* mask for indexed __u32 */ +#define CAP_TO_MASK(x) (1U << ((x) & 31)) /* mask for indexed __u32 */ #endif /* _UAPI_LINUX_CAPABILITY_H */ -- 2.35.1