diff options
| author | Roger Pau Monne <roger.pau@citrix.com> | 2013-01-16 18:01:06 +0100 |
|---|---|---|
| committer | William Pitcock <nenolod@dereferenced.org> | 2013-01-17 05:47:24 -0600 |
| commit | 4bd17e745b7eff551af9b206254d93c998432d2a (patch) | |
| tree | e74e6bb2b690d645555ab56ad5f510f492c6bdd3 /main/linux-grsec | |
| parent | 7bad3c33e39f342fbd280b56a4102689f1305f38 (diff) | |
| download | aports-4bd17e745b7eff551af9b206254d93c998432d2a.tar.bz2 aports-4bd17e745b7eff551af9b206254d93c998432d2a.tar.xz | |
linux-grsec: XSA-40
Diffstat (limited to 'main/linux-grsec')
| -rw-r--r-- | main/linux-grsec/APKBUILD | 4 | ||||
| -rw-r--r-- | main/linux-grsec/xsa40.patch | 56 |
2 files changed, 59 insertions, 1 deletions
diff --git a/main/linux-grsec/APKBUILD b/main/linux-grsec/APKBUILD index 6d100bd9d..b860ce45f 100644 --- a/main/linux-grsec/APKBUILD +++ b/main/linux-grsec/APKBUILD @@ -4,7 +4,7 @@ _flavor=grsec pkgname=linux-${_flavor} pkgver=3.6.11 _kernver=3.6 -pkgrel=2 +pkgrel=3 pkgdesc="Linux kernel with grsecurity" url=http://grsecurity.net depends="mkinitfs linux-firmware" @@ -18,6 +18,7 @@ source="http://ftp.kernel.org/pub/linux/kernel/v3.x/linux-$_kernver.tar.xz 0004-arp-flush-arp-cache-on-device-change.patch r8169-num-rx-desc.patch + xsa40.patch kernelconfig.x86 kernelconfig.x86_64 @@ -144,5 +145,6 @@ bd4bba74093405887d521309a74c19e9 patch-3.6.11.xz dce5c43ac3b5d8e35e245b35e90e1837 grsecurity-2.9.1-3.6.11-unofficial-1.patch 776adeeb5272093574f8836c5037dd7d 0004-arp-flush-arp-cache-on-device-change.patch daf2cbb558588c49c138fe9ca2482b64 r8169-num-rx-desc.patch +d9de28f8a74fe0347866705b4bd6db85 xsa40.patch 373db5888708938c6b1baed6da781fcb kernelconfig.x86 190788fb10e79abce9d570d5e87ec3b4 kernelconfig.x86_64" diff --git a/main/linux-grsec/xsa40.patch b/main/linux-grsec/xsa40.patch new file mode 100644 index 000000000..29db917cb --- /dev/null +++ b/main/linux-grsec/xsa40.patch @@ -0,0 +1,56 @@ +Xen: Fix stack corruption in xen_failsafe_callback for 32bit PVOPS guests. + +This fixes CVE-2013-0190 / XSA-40 + +There has been an error on the xen_failsafe_callback path for failed +iret, which causes the stack pointer to be wrong when entering the +iret_exc error path. This can result in the kernel crashing. + +In the classic kernel case, the relevant code looked a little like: + + popl %eax # Error code from hypervisor + jz 5f + addl $16,%esp + jmp iret_exc # Hypervisor said iret fault +5: addl $16,%esp + # Hypervisor said segment selector fault + +Here, there are two identical addls on either option of a branch which +appears to have been optimised by hoisting it above the jz, and +converting it to an lea, which leaves the flags register unaffected. + +In the PVOPS case, the code looks like: + + popl_cfi %eax # Error from the hypervisor + lea 16(%esp),%esp # Add $16 before choosing fault path + CFI_ADJUST_CFA_OFFSET -16 + jz 5f + addl $16,%esp # Incorrectly adjust %esp again + jmp iret_exc + +It is possible unprivileged userspace applications to cause this +behaviour, for example by loading an LDT code selector, then changing +the code selector to be not-present. At this point, there is a race +condition where it is possible for the hypervisor to return back to +userspace from an interrupt, fault on its own iret, and inject a +failsafe_callback into the kernel. + +This bug has been present since the introduction of Xen PVOPS support +in commit 5ead97c84 (xen: Core Xen implementation), in 2.6.23. + +Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com> +Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> + +diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S +index ff84d54..6ed91d9 100644 +--- a/arch/x86/kernel/entry_32.S ++++ b/arch/x86/kernel/entry_32.S +@@ -1065,7 +1065,6 @@ ENTRY(xen_failsafe_callback) + lea 16(%esp),%esp + CFI_ADJUST_CFA_OFFSET -16 + jz 5f +- addl $16,%esp + jmp iret_exc + 5: pushl_cfi $-1 /* orig_ax = -1 => not a system call */ + SAVE_ALL + |