Re: regression in 3.2-rc7 (kernel tried to execute NX-protected page)

[Josh Cartwright <joshc@linux.com>]

On Tue, Dec 27, 2011 at 08:48:13PM +0100, Ralf Hildebrandt wrote:
> from dmesg after booting today's git checkout:
> 
> ...
> [    6.366980] hpwdt: New timer passed in is 30 seconds.
> [    6.367040] kernel tried to execute NX-protected page - exploit attempt? (uid: 0)
> [    6.367113] BUG: unable to handle kernel paging request at c00f0000
> [    6.367232] IP: [<c00f0000>] 0xc00effff
> [    6.367318] *pdpt = 00000000013b1001 *pde = 00000000013de067 *pte = 80000000000f0163 
> [    6.367486] Oops: 0011 [#1] SMP 
> [    6.367600] Modules linked in: hpwdt(+) bnx2(+) psmouse container thermal button processor
> [    6.367927] 
> [    6.367976] Pid: 669, comm: modprobe Not tainted 3.2.0-rc7+ #17 HP ProLiant DL360 G5
> [    6.368002] EIP: 0060:[<c00f0000>] EFLAGS: 00010286 CPU: 1
> [    6.368002] EIP is at 0xc00f0000
> [    6.368002] EAX: 55524324 EBX: 00000000 ECX: 00000000 EDX: 00000000
> [    6.368002] ESI: 00000000 EDI: 00000000 EBP: f0783dd8 ESP: f0783da8
> [    6.368002]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
> [    6.368002] Process modprobe (pid: 669, ti=f0782000 task=f009db20 task.ti=f0782000)
> [    6.368002] Stack:
> [    6.368002]  f8426020 00000060 ffff007b 00000286 c00ffee0 ffffffed f0783dd8 f0783dd8
> [    6.368002]  c00f0000 00000001 00000000 c00f0000 f2cdbc00 f8426558 f8428100 c00f0000
> [    6.368002]  f2c30564 ffffffff f8428030 000f0000 000f0000 f2cfcea0 c0100000 c00f0000
> [    6.368002] Call Trace:
> [    6.368002]  [<f8426020>] ? asminline_call+0x20/0x46 [hpwdt]
> [    6.368002]  [<f8426558>] ? hpwdt_init_one+0x1a7/0x3c0 [hpwdt]
> [    6.368002]  [<c115dcf6>] ? pci_device_probe+0x47/0x68
> [    6.368002]  [<c11aa167>] ? driver_probe_device+0x4a/0x13a
> [    6.368002]  [<c115dbc4>] ? pci_match_device+0xf/0x8a
> [    6.368002]  [<c11aa2b9>] ? __driver_attach+0x62/0x64
> [    6.368002]  [<c11aa257>] ? driver_probe_device+0x13a/0x13a
> [    6.368002]  [<c11a9603>] ? bus_for_each_dev+0x3e/0x62
> [    6.368002]  [<c115dc62>] ? pci_dev_put+0xd/0xd
> [    6.368002]  [<c11a9f29>] ? driver_attach+0x19/0x1e
> [    6.368002]  [<c11aa257>] ? driver_probe_device+0x13a/0x13a
> [    6.368002]  [<c11a9cab>] ? bus_add_driver+0x17d/0x24d
> [    6.368002]  [<c115dc62>] ? pci_dev_put+0xd/0xd
> [    6.368002]  [<c11aa499>] ? driver_register+0x57/0xec
> [    6.368002]  [<c115e0af>] ? __pci_register_driver+0x31/0x92
> [    6.368002]  [<c1001027>] ? do_one_initcall+0x27/0x150
> [    6.368002]  [<c101c97e>] ? set_memory_nx+0x57/0x5b
> [    6.368002]  [<f842b000>] ? 0xf842afff
> [    6.368002]  [<c1054426>] ? sys_init_module+0xdff/0x1a14
> [    6.368002]  [<c126fa97>] ? sysenter_do_call+0x12/0x26
> [    6.368002] Code: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff <90> 90 80 fc d8 75 0d e9 da 06 00 00 69 04 00 00 ad 04 00 00 9c 
> [    6.368002] EIP: [<c00f0000>] 0xc00f0000 SS:ESP 0068:f0783da8
> [    6.368002] CR2: 00000000c00f0000
> [    6.368002] ---[ end trace 865af1d8b782ff50 ]---
> [    6.487054] bnx2 0000:03:00.0: BAR 0: set to [mem 0xf8000000-0xf9ffffff 64bit] (PCI address [0xf8000000-0xf9ffffff])
> ...

It looks like this is the fix you are looking for, but it hasn't yet
landed in Linus' tree.  Four minutes before you sent this message Wim
sent off a pull request, so hopefully you'll see it there soon.


commit e67d668e147c3b4fec638c9e0ace04319f5ceccd
Author: Mingarelli, Thomas <Thomas.Mingarelli@hp.com>
Date:   Mon Nov 7 10:59:00 2011 +0100

    watchdog: hpwdt: Changes to handle NX secure bit in 32bit path
    
    This patch makes use of the set_memory_x() kernel API in order
    to make necessary BIOS calls to source NMIs.
    
    This is needed for SLES11 SP2 and the latest upstream kernel as it appears
    the NX Execute Disable has grown in its control.
    
    Signed-off by: Thomas Mingarelli <thomas.mingarelli@hp.com>
    Signed-off by: Wim Van Sebroeck <wim@iguana.be>
    Cc: stable@kernel.org

diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c
index 3774c9b..8464ea1 100644
--- a/drivers/watchdog/hpwdt.c
+++ b/drivers/watchdog/hpwdt.c
@@ -231,6 +231,7 @@ static int __devinit cru_detect(unsigned long map_entry,
 
 	cmn_regs.u1.reax = CRU_BIOS_SIGNATURE_VALUE;
 
+	set_memory_x((unsigned long)bios32_entrypoint, (2 * PAGE_SIZE));
 	asminline_call(&cmn_regs, bios32_entrypoint);
 
 	if (cmn_regs.u1.ral != 0) {
@@ -248,8 +249,10 @@ static int __devinit cru_detect(unsigned long map_entry,
 		if ((physical_bios_base + physical_bios_offset)) {
 			cru_rom_addr =
 				ioremap(cru_physical_address, cru_length);
-			if (cru_rom_addr)
+			if (cru_rom_addr) {
+				set_memory_x((unsigned long)cru_rom_addr, cru_length);
 				retval = 0;
+			}
 		}
 
 		printk(KERN_DEBUG "hpwdt: CRU Base Address:   0x%lx\n",

-- 
                           joshc