diff options
| author | Dan Rosenberg <drosenberg@vsecurity.com> | 2011-06-15 15:09:01 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-08-08 10:23:18 -0700 |
| commit | 2beffeba8046011cf87062b842327328fb22cda7 (patch) | |
| tree | 6aca6f13e4320d308a20f78ca529cf74ba39cbe6 | |
| parent | 35ed3d0fb62804090a3f21a7ce84c538a6ff852f (diff) | |
| download | lwn-2beffeba8046011cf87062b842327328fb22cda7.tar.gz lwn-2beffeba8046011cf87062b842327328fb22cda7.zip | |
alpha: fix several security issues
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>
| -rw-r--r-- | arch/alpha/kernel/osf_sys.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c index 62619f25132f..a94e49c340fb 100644 --- a/arch/alpha/kernel/osf_sys.c +++ b/arch/alpha/kernel/osf_sys.c @@ -431,7 +431,7 @@ SYSCALL_DEFINE2(osf_getdomainname, char __user *, name, int, namelen) 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, command, char __user *, buf, long, count) 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 long, op, void __user *, buffer, 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, int __user *, ustatus, int, options, { 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, int __user *, ustatus, int, options, 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); |