Messages in this thread Patch in this message | | | Date | Fri, 05 Aug 2011 17:02:19 -0700 | From | Greg KH <> | Subject | [49/55] alpha: fix several security issues |
| |
2.6.32-longterm review patch. If anyone has any objections, please let us know.
------------------
From: Dan Rosenberg <drosenberg@vsecurity.com>
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 <drosenberg@vsecurity.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- arch/alpha/kernel/osf_sys.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
--- a/arch/alpha/kernel/osf_sys.c +++ b/arch/alpha/kernel/osf_sys.c @@ -431,7 +431,7 @@ SYSCALL_DEFINE2(osf_getdomainname, char return -EFAULT; len = namelen; - if (namelen > 32) + if (len > 32) len = 32; down_read(&uts_sem); @@ -618,7 +618,7 @@ SYSCALL_DEFINE3(osf_sysinfo, int, comman 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; @@ -673,7 +673,7 @@ SYSCALL_DEFINE5(osf_getsysinfo, unsigned 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; @@ -1035,6 +1035,7 @@ SYSCALL_DEFINE4(osf_wait4, pid_t, pid, i { struct rusage r; long ret, err; + unsigned int status = 0; mm_segment_t old_fs; if (!ur) @@ -1043,13 +1044,15 @@ SYSCALL_DEFINE4(osf_wait4, pid_t, pid, i 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);
| |