From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Eddy Wu <itseddy0402@gmail.com>, Eddy Wu <eddy_wu@trendmicro.com>,
Oleg Nesterov <oleg@redhat.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 5.4 42/42] fork: fix copy_process(CLONE_PARENT) race with the exiting ->real_parent
Date: Mon, 9 Nov 2020 22:54:40 -0500 [thread overview]
Message-ID: <20201110035440.424258-42-sashal@kernel.org> (raw)
In-Reply-To: <20201110035440.424258-1-sashal@kernel.org>
From: Eddy Wu <itseddy0402@gmail.com>
[ Upstream commit b4e00444cab4c3f3fec876dc0cccc8cbb0d1a948 ]
current->group_leader->exit_signal may change during copy_process() if
current->real_parent exits.
Move the assignment inside tasklist_lock to avoid the race.
Signed-off-by: Eddy Wu <eddy_wu@trendmicro.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/fork.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/kernel/fork.c b/kernel/fork.c
index e3d5963d8c6f5..419fff8eb9e55 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2100,14 +2100,9 @@ static __latent_entropy struct task_struct *copy_process(
/* ok, now we should be set up.. */
p->pid = pid_nr(pid);
if (clone_flags & CLONE_THREAD) {
- p->exit_signal = -1;
p->group_leader = current->group_leader;
p->tgid = current->tgid;
} else {
- if (clone_flags & CLONE_PARENT)
- p->exit_signal = current->group_leader->exit_signal;
- else
- p->exit_signal = args->exit_signal;
p->group_leader = p;
p->tgid = p->pid;
}
@@ -2152,9 +2147,14 @@ static __latent_entropy struct task_struct *copy_process(
if (clone_flags & (CLONE_PARENT|CLONE_THREAD)) {
p->real_parent = current->real_parent;
p->parent_exec_id = current->parent_exec_id;
+ if (clone_flags & CLONE_THREAD)
+ p->exit_signal = -1;
+ else
+ p->exit_signal = current->group_leader->exit_signal;
} else {
p->real_parent = current;
p->parent_exec_id = current->self_exec_id;
+ p->exit_signal = args->exit_signal;
}
klp_copy_process(p);
--
2.27.0
prev parent reply other threads:[~2020-11-10 3:55 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-10 3:53 [PATCH AUTOSEL 5.4 01/42] ASoC: qcom: sdm845: set driver name correctly Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 02/42] ASoC: cs42l51: manage mclk shutdown delay Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 03/42] usb: dwc3: pci: add support for the Intel Alder Lake-S Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 04/42] opp: Reduce the size of critical section in _opp_table_kref_release() Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 05/42] usb: gadget: goku_udc: fix potential crashes in probe Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 06/42] selftests/ftrace: check for do_sys_openat2 in user-memory test Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 07/42] selftests: pidfd: fix compilation errors due to wait.h Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 08/42] ALSA: hda: Separate runtime and system suspend Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 09/42] ALSA: hda: Reinstate runtime_allow() for all hda controllers Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 10/42] gfs2: Free rd_bits later in gfs2_clear_rgrpd to fix use-after-free Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 11/42] gfs2: Add missing truncate_inode_pages_final for sd_aspace Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 12/42] gfs2: check for live vs. read-only file system in gfs2_fitrim Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 13/42] scsi: hpsa: Fix memory leak in hpsa_init_one() Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 14/42] drm/amdgpu: perform srbm soft reset always on SDMA resume Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 15/42] drm/amd/pm: perform SMC reset on suspend/hibernation Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 16/42] drm/amd/pm: do not use ixFEATURE_STATUS for checking smc running Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 17/42] mac80211: fix use of skb payload instead of header Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 18/42] cfg80211: initialize wdev data earlier Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 19/42] mac80211: always wind down STA state Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 20/42] cfg80211: regulatory: Fix inconsistent format argument Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 21/42] tracing: Fix the checking of stackidx in __ftrace_trace_stack Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 22/42] scsi: scsi_dh_alua: Avoid crash during alua_bus_detach() Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 23/42] scsi: mpt3sas: Fix timeouts observed while reenabling IRQ Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 24/42] nvme: introduce nvme_sync_io_queues Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 25/42] nvme-rdma: avoid race between time out and tear down Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 26/42] nvme-tcp: " Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 27/42] nvme-rdma: avoid repeated request completion Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 28/42] nvme-tcp: " Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 29/42] iommu/amd: Increase interrupt remapping table limit to 512 entries Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 30/42] s390/smp: move rcu_cpu_starting() earlier Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 31/42] vfio: platform: fix reference leak in vfio_platform_open Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 32/42] vfio/pci: Bypass IGD init in case of -ENODEV Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 33/42] i2c: mediatek: move dma reset before i2c reset Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 34/42] net: usb: qmi_wwan: add Telit LE910Cx 0x1230 composition Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 35/42] amd/amdgpu: Disable VCN DPG mode for Picasso Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 36/42] kprobes: Tell lockdep about kprobe nesting Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 37/42] selftests: proc: fix warning: _GNU_SOURCE redefined Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 38/42] riscv: Set text_offset correctly for M-Mode Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 39/42] i2c: sh_mobile: implement atomic transfers Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 40/42] tpm_tis: Disable interrupts on ThinkPad T490s Sasha Levin
2020-11-10 3:54 ` [PATCH AUTOSEL 5.4 41/42] vt: Disable KD_FONT_OP_COPY Sasha Levin
2020-11-10 3:54 ` Sasha Levin [this message]
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