From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120205220951.033873980@pcw.home.local> Date: Sun, 05 Feb 2012 23:10:26 +0100 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Dan Rosenberg , Richard Henderson , Ivan Kokshaysky , Matt Turner , Andrew Morton , Linus Torvalds , Greg KH Subject: [PATCH 37/91] alpha: fix several security issues In-Reply-To: <0635750f5f06ed2ca212b91fcb5c4483@local> Sender: linux-kernel-owner@vger.kernel.org List-ID: 2.6.27-longterm review patch. If anyone has any objections, please let us know. ------------------ commit 21c5977a836e399fc710ff2c5367845ed5c2527f upstream. Fix several security issues in Alpha-specific syscalls. Untested, but mostly trivial. 1. Signedness issue in osf_getdomainname allows copying out-of-bounds kernel memory to userland. 2. Signedness issue in osf_sysinfo allows copying large amounts of kernel memory to userland. 3. Typo (?) in osf_getsysinfo bounds minimum instead of maximum copy size, allowing copying large amounts of kernel memory to userland. 4. Usage of user pointer in osf_wait4 while under KERNEL_DS allows privilege escalation via writing return value of sys_wait4 to kernel memory. Signed-off-by: Dan Rosenberg Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/alpha/kernel/osf_sys.c | 11 +++++++---- 1 files changed, 7 insertions(+), 4 deletions(-) Index: longterm-2.6.27/arch/alpha/kernel/osf_sys.c =================================================================== --- longterm-2.6.27.orig/arch/alpha/kernel/osf_sys.c 2012-02-05 22:34:33.893915202 +0100 +++ longterm-2.6.27/arch/alpha/kernel/osf_sys.c 2012-02-05 22:34:40.104915063 +0100 @@ -451,7 +451,7 @@ return -EFAULT; len = namelen; - if (namelen > 32) + if (len > 32) len = 32; down_read(&uts_sem); @@ -639,7 +639,7 @@ down_read(&uts_sem); res = sysinfo_table[offset]; len = strlen(res)+1; - if (len > count) + if ((unsigned long)len > (unsigned long)count) len = count; if (copy_to_user(buf, res, len)) err = -EFAULT; @@ -695,7 +695,7 @@ return 1; case GSI_GET_HWRPB: - if (nbytes < sizeof(*hwrpb)) + if (nbytes > sizeof(*hwrpb)) return -EINVAL; if (copy_to_user(buffer, hwrpb, nbytes) != 0) return -EFAULT; @@ -1061,6 +1061,7 @@ { struct rusage r; long ret, err; + unsigned int status = 0; mm_segment_t old_fs; if (!ur) @@ -1069,13 +1070,15 @@ old_fs = get_fs(); set_fs (KERNEL_DS); - ret = sys_wait4(pid, ustatus, options, (struct rusage __user *) &r); + ret = sys_wait4(pid, (unsigned int __user *) &status, options, + (struct rusage __user *) &r); set_fs (old_fs); if (!access_ok(VERIFY_WRITE, ur, sizeof(*ur))) return -EFAULT; err = 0; + err |= put_user(status, ustatus); err |= __put_user(r.ru_utime.tv_sec, &ur->ru_utime.tv_sec); err |= __put_user(r.ru_utime.tv_usec, &ur->ru_utime.tv_usec); err |= __put_user(r.ru_stime.tv_sec, &ur->ru_stime.tv_sec);