Messages in this thread Patch in this message |  | | | From | Andi Kleen <> | | Subject | [PATCH] [97/99] alpha: fix several security issues | | Date | Wed, 27 Jul 2011 14:49:37 -0700 (PDT) |
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2.6.35-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Dan Rosenberg <drosenberg@vsecurity.com> [ upstream commit 21c5977a836e399fc710ff2c5367845ed5c2527f ]
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.
Said to fix CVE-2011-2208 to CVE-2011-2211
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: Andi Kleen <ak@linux.intel.com>
Index: linux-2.6.35.y/arch/alpha/kernel/osf_sys.c =================================================================== --- linux-2.6.35.y.orig/arch/alpha/kernel/osf_sys.c +++ linux-2.6.35.y/arch/alpha/kernel/osf_sys.c @@ -432,7 +432,7 @@ SYSCALL_DEFINE2(osf_getdomainname, char return -EFAULT; len = namelen; - if (namelen > 32) + if (len > 32) len = 32; down_read(&uts_sem); @@ -619,7 +619,7 @@ 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; @@ -674,7 +674,7 @@ 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; @@ -1036,6 +1036,7 @@ 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) @@ -1044,13 +1045,15 @@ 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);
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