Messages in this thread | | | From | "Luis R. Rodriguez" <> | Date | Mon, 15 May 2017 16:45:21 -0700 | Subject | Re: next-20170515: WARNING: CPU: 0 PID: 1 at arch/x86/mm/dump_pagetables.c:236 note_page+0x630/0x7e0 |
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On Mon, May 15, 2017 at 3:57 PM, Kees Cook <keescook@chromium.org> wrote: > On Mon, May 15, 2017 at 3:15 PM, Luis R. Rodriguez <mcgrof@kernel.org> wrote: >> On Tue, May 16, 2017 at 12:06:50AM +0200, Luis R. Rodriguez wrote: >>> Using QEMU emulator version 2.7.94 (v2.8.0-rc4-dirty) >>> >>> I will try updating my distro package for qemu and see if perhaps its this >>> and for the other odd fork issue I reported [0]. >>> >>> [0] https://lkml.kernel.org/r/CAB=NE6VZXq3y-3pfouYTBUco2Cq2xqoLZrgDFdVx+_=_=SwG_Q@mail.gmail.com >> >> Yeah nope, using my distribution latest: >> >> QEMU emulator version 2.8.0(openSUSE Tumbleweed) >> >> And still both issues are present. >> >> Luis > > Can you enable CONFIG_X86_PTDUMP=y and then find out what is located > at ffffffffc0288000 via /sys/kernel/debug/kernel_page_tables ?
Sure thing.
Recompiled with this enabled, new warning:
[ 0.891559] x86/mm: Found insecure W+X mapping at address ffffffffc00e4000/0xffffffffc00e4000 [ 0.892394] ------------[ cut here ]------------ [ 0.892834] WARNING: CPU: 0 PID: 1 at arch/x86/mm/dump_pagetables.c:236 note_page+0x630/0x7e0 [ 0.893674] Modules linked in: [ 0.893972] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.12.0-rc1-next-20170515+ #145 [ 0.894687] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 [ 0.895828] task: ffff8ed7fa5ccc80 task.stack: ffffae3900630000 [ 0.896403] RIP: 0010:note_page+0x630/0x7e0 [ 0.896780] RSP: 0018:ffffae3900633df0 EFLAGS: 00010286 [ 0.897271] RAX: 0000000000000051 RBX: ffffae3900633e88 RCX: ffffffff9b456708 [ 0.897940] RDX: 0000000000000000 RSI: 0000000000000096 RDI: 0000000000000246 [ 0.898624] RBP: ffffae3900633e28 R08: 203a6d6d2f363878 R09: 0000000000000165 [ 0.899314] R10: ffffae3900633dd8 R11: 736e6920646e756f R12: 0000000000000000 [ 0.899987] R13: 0000000000000004 R14: 0000000000000000 R15: 0000000000000000 [ 0.900629] FS: 0000000000000000(0000) GS:ffff8ed7ffc00000(0000) knlGS:0000000000000000 [ 0.901398] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.901908] CR2: 0000000000000000 CR3: 0000000118009000 CR4: 00000000000006f0 [ 0.902590] Call Trace: [ 0.902827] ptdump_walk_pgd_level_core+0x3e7/0x490 [ 0.903274] ? 0xffffffff9a800000 [ 0.903595] ptdump_walk_pgd_level_checkwx+0x17/0x20 [ 0.904064] mark_rodata_ro+0xf4/0x100 [ 0.904423] ? rest_init+0x80/0x80 [ 0.904744] kernel_init+0x2f/0x100 [ 0.905068] ret_from_fork+0x2c/0x40 [ 0.905393] Code: 48 c7 43 28 00 00 00 00 48 89 43 20 e9 05 fd ff ff 48 8b 73 10 48 c7 c7 28 36 1e 9b c6 05 c8 eb bc 00 01 48 89 f2 e8 cd fc 11 00 <0f> ff e9 1f fa ff ff 48 8b 70 20 48 c7 c7 65 b2 1e 9b e8 b6 fc [ 0.907173] ---[ end trace 878b39cb0c248e66 ]--- [ 0.907655] x86/mm: Checked W+X mappings: FAILED, 1 W+X pages found.
And ffffffffc00e4000 is:
---[ Modules ]--- 0xffffffffc0000000-0xffffffffc00e4000 912K pte 0xffffffffc00e4000-0xffffffffc00e5000 4K RW GLB x pte
In case someone needs the full /sys/kernel/debug/kernel_page_tables file:
http://drvbp1.linux-foundation.org/~mcgrof/2017/05/15/kernel_page_tables/piggy-4.12.0-rc1-next-20170515-page-tables.txt
Luis
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