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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Andrea Arcangeli <aarcange@redhat.com>,
	Rik van Riel <riel@surriel.com>, Roman Gushchin <guro@fb.com>,
	Michal Hocko <mhocko@suse.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 5.1 38/39] fork,memcg: alloc_thread_stack_node needs to set tsk->stack
Date: Tue,  2 Jul 2019 22:15:13 -0400	[thread overview]
Message-ID: <20190703021514.17727-38-sashal@kernel.org> (raw)
In-Reply-To: <20190703021514.17727-1-sashal@kernel.org>

From: Andrea Arcangeli <aarcange@redhat.com>

[ Upstream commit 1bf4580e00a248a2c86269125390eb3648e1877c ]

Commit 5eed6f1dff87 ("fork,memcg: fix crash in free_thread_stack on
memcg charge fail") corrected two instances, but there was a third
instance of this bug.

Without setting tsk->stack, if memcg_charge_kernel_stack fails, it'll
execute free_thread_stack() on a dangling pointer.

Enterprise kernels are compiled with VMAP_STACK=y so this isn't
critical, but custom VMAP_STACK=n builds should have some performance
advantage, with the drawback of risking to fail fork because compaction
didn't succeed.  So as long as VMAP_STACK=n is a supported option it's
worth fixing it upstream.

Link: http://lkml.kernel.org/r/20190619011450.28048-1-aarcange@redhat.com
Fixes: 9b6f7e163cd0 ("mm: rework memcg kernel stack accounting")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: Rik van Riel <riel@surriel.com>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 kernel/fork.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/kernel/fork.c b/kernel/fork.c
index 2628f3773ca8..ee24fea0eede 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -245,7 +245,11 @@ static unsigned long *alloc_thread_stack_node(struct task_struct *tsk, int node)
 	struct page *page = alloc_pages_node(node, THREADINFO_GFP,
 					     THREAD_SIZE_ORDER);
 
-	return page ? page_address(page) : NULL;
+	if (likely(page)) {
+		tsk->stack = page_address(page);
+		return tsk->stack;
+	}
+	return NULL;
 #endif
 }
 
-- 
2.20.1


  parent reply	other threads:[~2019-07-03  2:21 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-03  2:14 [PATCH AUTOSEL 5.1 01/39] ARM: dts: meson8: fix GPU interrupts and drop an undocumented property Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 02/39] ARM: dts: meson8b: fix the operating voltage of the Mali GPU Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 03/39] idr: Fix idr_get_next race with idr_remove Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 04/39] irqchip/irq-csky-mpintc: Support auto irq deliver to all cpus Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 05/39] irqchip/gic-v3-its: Fix command queue pointer comparison bug Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 06/39] clk: ti: clkctrl: Fix returning uninitialized data Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 07/39] efi/bgrt: Drop BGRT status field reserved bits check Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 08/39] arm64: dts: ls1028a: Fix CPU idle fail Sasha Levin
2019-07-11  5:04   ` Ran Wang
2019-07-11  6:43     ` Greg KH
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 09/39] selftests/powerpc: Add test of fork with mapping above 512TB Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 10/39] perf/core: Fix perf_sample_regs_user() mm check Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 11/39] ARM: dts: gemini Fix up DNS-313 compatible string Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 12/39] ARM: omap2: remove incorrect __init annotation Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 13/39] afs: Fix uninitialised spinlock afs_volume::cb_break_lock Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 14/39] x86/efi: fix a -Wtype-limits compilation warning Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 15/39] x86/apic: Fix integer overflow on 10 bit left shift of cpu_khz Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 16/39] be2net: fix link failure after ethtool offline test Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 17/39] ppp: mppe: Add softdep to arc4 Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 18/39] net: stmmac: fixed new system time seconds value calculation Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 19/39] net: stmmac: set IC bit when transmitting frames with HW timestamp Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 20/39] sis900: fix TX completion Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 21/39] ARM: dts: imx6ul: fix PWM[1-4] interrupts Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 22/39] qmi_wwan: Fix out-of-bounds read Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 23/39] pinctrl: mcp23s08: Fix add_data and irqchip_add_nested call order Sasha Levin
2019-07-03  2:14 ` [PATCH AUTOSEL 5.1 24/39] pinctrl: ocelot: fix gpio direction for pins after 31 Sasha Levin
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 25/39] pinctrl: ocelot: fix pinmuxing " Sasha Levin
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 26/39] dm table: don't copy from a NULL pointer in realloc_argv() Sasha Levin
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 27/39] dm verity: use message limit for data block corruption message Sasha Levin
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 28/39] x86/boot/64: Fix crash if kernel image crosses page table boundary Sasha Levin
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 29/39] x86/boot/64: Add missing fixup_pointer() for next_early_pgt access Sasha Levin
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 30/39] HID: chicony: add another quirk for PixArt mouse Sasha Levin
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 31/39] HID: uclogic: Add support for Huion HS64 tablet Sasha Levin
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 32/39] HID: multitouch: Add pointstick support for ALPS Touchpad Sasha Levin
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 33/39] pinctrl: mediatek: Ignore interrupts that are wake only during resume Sasha Levin
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 34/39] net: aquantia: fix vlans not working over bridged network Sasha Levin
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 35/39] cpu/hotplug: Fix out-of-bounds read when setting fail state Sasha Levin
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 36/39] pinctrl: mediatek: Update cur_mask in mask/mask ops Sasha Levin
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 37/39] mm/oom_kill.c: fix uninitialized oc->constraint Sasha Levin
2019-07-03  2:15 ` Sasha Levin [this message]
2019-07-03  2:15 ` [PATCH AUTOSEL 5.1 39/39] linux/kernel.h: fix overflow for DIV_ROUND_UP_ULL Sasha Levin

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