Commit 7489161b authored by Murad Masimov's avatar Murad Masimov Committed by Steve French
Browse files

cifs: Fix integer overflow while processing acregmax mount option 



User-provided mount parameter acregmax of type u32 is intended to have
an upper limit, but before it is validated, the value is converted from
seconds to jiffies which can lead to an integer overflow.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 57804646 ("cifs: Add new parameter "acregmax" for distinct file and directory metadata timeout")
Signed-off-by: default avatarMurad Masimov <m.masimov@mt-integration.ru>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent fc99045e

fs/smb/client/fs_context.c

+2 −2
Original line number Diff line number Diff line
@@ -1344,11 +1344,11 @@ static int smb3_fs_context_parse_param(struct fs_context *fc, 
		}

		break;

	case Opt_acregmax:

		ctx->acregmax = HZ * result.uint_32;

		if (ctx->acregmax > CIFS_MAX_ACTIMEO) {

		if (result.uint_32 > CIFS_MAX_ACTIMEO / HZ) {

			cifs_errorf(fc, "acregmax too large\n");

			goto cifs_parse_mount_err;

		}

		ctx->acregmax = HZ * result.uint_32;

		break;

	case Opt_acdirmax:

		ctx->acdirmax = HZ * result.uint_32;