The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From feb8e960d780e170e992a70491eec9dd68f4dbf2 Mon Sep 17 00:00:00 2001
From: Christophe Leroy <christophe.leroy(a)c-s.fr>
Date: Fri, 17 Apr 2020 11:58:36 +0000
Subject: [PATCH] powerpc/mm: Fix CONFIG_PPC_KUAP_DEBUG on PPC32
CONFIG_PPC_KUAP_DEBUG is not selectable because it depends on PPC_32
which doesn't exists.
Fixing it leads to a deadlock due to a vital register getting
clobbered in _switch().
Change dependency to PPC32 and use r0 instead of r4 in _switch()
Fixes: e2fb9f544431 ("powerpc/32: Prepare for Kernel Userspace Access Protection")
Cc: stable(a)vger.kernel.org # v5.2+
Signed-off-by: Christophe Leroy <christophe.leroy(a)c-s.fr>
Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au>
Link: https://lore.kernel.org/r/540242f7d4573f7cdf1b3bf46bb35f743b2cd68f.15871246…
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index a6371fb8f761..8420abd4ea1c 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -732,7 +732,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_SPE)
stw r10,_CCR(r1)
stw r1,KSP(r3) /* Set old stack pointer */
- kuap_check r2, r4
+ kuap_check r2, r0
#ifdef CONFIG_SMP
/* We need a sync somewhere here to make sure that if the
* previous task gets rescheduled on another CPU, it sees all
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 0c3c1902135c..27a81c291be8 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -397,7 +397,7 @@ config PPC_KUAP
config PPC_KUAP_DEBUG
bool "Extra debugging for Kernel Userspace Access Protection"
- depends on PPC_KUAP && (PPC_RADIX_MMU || PPC_32)
+ depends on PPC_KUAP && (PPC_RADIX_MMU || PPC32)
help
Add extra debugging for Kernel Userspace Access Protection (KUAP)
If you're unsure, say N.
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 0fe0781f29dd8ab618999e6bda33c782ebbdb109 Mon Sep 17 00:00:00 2001
From: Paulo Alcantara <pc(a)cjr.nz>
Date: Mon, 20 Apr 2020 23:44:24 -0300
Subject: [PATCH] cifs: fix uninitialised lease_key in open_shroot()
SMB2_open_init() expects a pre-initialised lease_key when opening a
file with a lease, so set pfid->lease_key prior to calling it in
open_shroot().
This issue was observed when performing some DFS failover tests and
the lease key was never randomly generated.
Signed-off-by: Paulo Alcantara (SUSE) <pc(a)cjr.nz>
Signed-off-by: Steve French <stfrench(a)microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber(a)redhat.com>
Reviewed-by: Aurelien Aptel <aaptel(a)suse.com>
CC: Stable <stable(a)vger.kernel.org>
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index b36c46f48705..f829f4165d38 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -687,6 +687,11 @@ int open_shroot(unsigned int xid, struct cifs_tcon *tcon,
if (smb3_encryption_required(tcon))
flags |= CIFS_TRANSFORM_REQ;
+ if (!server->ops->new_lease_key)
+ return -EIO;
+
+ server->ops->new_lease_key(pfid);
+
memset(rqst, 0, sizeof(rqst));
resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER;
memset(rsp_iov, 0, sizeof(rsp_iov));
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From b61c38baa98056d4802ff5be5cfb979efc2d0f7a Mon Sep 17 00:00:00 2001
From: Christophe Leroy <christophe.leroy(a)c-s.fr>
Date: Mon, 20 Apr 2020 05:37:42 +0000
Subject: [PATCH] powerpc/8xx: Fix STRICT_KERNEL_RWX startup test failure
WRITE_RO lkdtm test works.
But when selecting CONFIG_DEBUG_RODATA_TEST, the kernel reports
rodata_test: test data was not read only
This is because when rodata test runs, there are still old entries
in TLB.
Flush TLB after setting kernel pages RO or NX.
Fixes: d5f17ee96447 ("powerpc/8xx: don't disable large TLBs with CONFIG_STRICT_KERNEL_RWX")
Cc: stable(a)vger.kernel.org # v5.1+
Signed-off-by: Christophe Leroy <christophe.leroy(a)c-s.fr>
Signed-off-by: Michael Ellerman <mpe(a)ellerman.id.au>
Link: https://lore.kernel.org/r/485caac75f195f18c11eb077b0031fdd2bb7fb9e.15873610…
diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index 3189308dece4..d83a12c5bc7f 100644
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -185,6 +185,7 @@ void mmu_mark_initmem_nx(void)
mmu_mapin_ram_chunk(etext8, einittext8, PAGE_KERNEL);
}
}
+ _tlbil_all();
}
#ifdef CONFIG_STRICT_KERNEL_RWX
@@ -199,6 +200,8 @@ void mmu_mark_rodata_ro(void)
~(LARGE_PAGE_SIZE_8M - 1)));
mmu_patch_addis(&patch__dtlbmiss_romem_top, -__pa(_sinittext));
+ _tlbil_all();
+
/* Update page tables for PTDUMP and BDI */
mmu_mapin_ram_chunk(0, sinittext, __pgprot(0));
mmu_mapin_ram_chunk(0, etext, PAGE_KERNEL_ROX);
This patch is an improvement of a previous version[1], as the previous
version is not easy to understand.
This issue persists in the newest kernel, I have to resend the fix. As
the implementation is changed, I drop Roman's ack from the previous
version.
Here's the explanation of this issue.
memory.{low,min} won't take effect if the to-be-reclaimed memcg is the
sc->target_mem_cgroup, that can also be proved by the implementation in
mem_cgroup_protected(), see bellow,
mem_cgroup_protected
if (memcg == root) [2]
return MEMCG_PROT_NONE;
But this rule is ignored in mem_cgroup_protection(), which will read
memory.{emin, elow} as the protection whatever the memcg is.
How would this issue happen?
Because in mem_cgroup_protected() we forget to clear the
memory.{emin, elow} if the memcg is target_mem_cgroup [2].
An example to illustrate this issue.
root_mem_cgroup
/
A memory.max: 1024M
memory.min: 512M
memory.current: 800M ('current' must be greater than 'min')
Once kswapd starts to reclaim memcg A, it assigns 512M to memory.emin of A.
Then kswapd stops.
As a result of it, the memory values of A will be,
root_mem_cgroup
/
A memory.max: 1024M
memory.min: 512M
memory.current: 512M (approximately)
memory.emin: 512M
Then a new workload starts to run in memcg A, and it will trigger memcg
relcaim in A soon. As memcg A is the target_mem_cgroup of this
reclaimer, so it return directly without touching memory.{emin, elow}.[2]
The memory values of A will be,
root_mem_cgroup
/
A memory.max: 1024M
memory.min: 512M
memory.current: 1024M (approximately)
memory.emin: 512M
Then this memory.emin will be used in mem_cgroup_protection() to get the
scan count, which is obvoiusly a wrong scan count.
[1]. https://lore.kernel.org/linux-mm/20200216145249.6900-1-laoar.shao@gmail.com/
Fixes: 9783aa9917f8 ("mm, memcg: proportional memory.{low,min} reclaim")
Cc: Chris Down <chris(a)chrisdown.name>
Cc: Roman Gushchin <guro(a)fb.com>
Cc: stable(a)vger.kernel.org
Signed-off-by: Yafang Shao <laoar.shao(a)gmail.com>
---
include/linux/memcontrol.h | 13 +++++++++++--
mm/vmscan.c | 4 ++--
2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index d275c72c4f8e..114cfe06bf60 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -344,12 +344,20 @@ static inline bool mem_cgroup_disabled(void)
return !cgroup_subsys_enabled(memory_cgrp_subsys);
}
-static inline unsigned long mem_cgroup_protection(struct mem_cgroup *memcg,
+static inline unsigned long mem_cgroup_protection(struct mem_cgroup *root,
+ struct mem_cgroup *memcg,
bool in_low_reclaim)
{
if (mem_cgroup_disabled())
return 0;
+ /*
+ * Memcg protection won't take effect if the memcg is the target
+ * root memcg.
+ */
+ if (root == memcg)
+ return 0;
+
if (in_low_reclaim)
return READ_ONCE(memcg->memory.emin);
@@ -835,7 +843,8 @@ static inline void memcg_memory_event_mm(struct mm_struct *mm,
{
}
-static inline unsigned long mem_cgroup_protection(struct mem_cgroup *memcg,
+static inline unsigned long mem_cgroup_protection(struct mem_cgroup *root,
+ struct mem_cgroup *memcg,
bool in_low_reclaim)
{
return 0;
diff --git a/mm/vmscan.c b/mm/vmscan.c
index b06868fc4926..ad2782f754ab 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2346,9 +2346,9 @@ static void get_scan_count(struct lruvec *lruvec, struct scan_control *sc,
unsigned long protection;
lruvec_size = lruvec_lru_size(lruvec, lru, sc->reclaim_idx);
- protection = mem_cgroup_protection(memcg,
+ protection = mem_cgroup_protection(sc->target_mem_cgroup,
+ memcg,
sc->memcg_low_reclaim);
-
if (protection) {
/*
* Scale a cgroup's reclaim pressure by proportioning
--
2.18.2
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 61e713bdca3678e84815f2427f7a063fc353a1fc Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm(a)xmission.com>
Date: Mon, 20 Apr 2020 11:41:50 -0500
Subject: [PATCH] signal: Avoid corrupting si_pid and si_uid in
do_notify_parent
Christof Meerwald <cmeerw(a)cmeerw.org> writes:
> Hi,
>
> this is probably related to commit
> 7a0cf094944e2540758b7f957eb6846d5126f535 (signal: Correct namespace
> fixups of si_pid and si_uid).
>
> With a 5.6.5 kernel I am seeing SIGCHLD signals that don't include a
> properly set si_pid field - this seems to happen for multi-threaded
> child processes.
>
> A simple test program (based on the sample from the signalfd man page):
>
> #include <sys/signalfd.h>
> #include <signal.h>
> #include <unistd.h>
> #include <spawn.h>
> #include <stdlib.h>
> #include <stdio.h>
>
> #define handle_error(msg) \
> do { perror(msg); exit(EXIT_FAILURE); } while (0)
>
> int main(int argc, char *argv[])
> {
> sigset_t mask;
> int sfd;
> struct signalfd_siginfo fdsi;
> ssize_t s;
>
> sigemptyset(&mask);
> sigaddset(&mask, SIGCHLD);
>
> if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1)
> handle_error("sigprocmask");
>
> pid_t chldpid;
> char *chldargv[] = { "./sfdclient", NULL };
> posix_spawn(&chldpid, "./sfdclient", NULL, NULL, chldargv, NULL);
>
> sfd = signalfd(-1, &mask, 0);
> if (sfd == -1)
> handle_error("signalfd");
>
> for (;;) {
> s = read(sfd, &fdsi, sizeof(struct signalfd_siginfo));
> if (s != sizeof(struct signalfd_siginfo))
> handle_error("read");
>
> if (fdsi.ssi_signo == SIGCHLD) {
> printf("Got SIGCHLD %d %d %d %d\n",
> fdsi.ssi_status, fdsi.ssi_code,
> fdsi.ssi_uid, fdsi.ssi_pid);
> return 0;
> } else {
> printf("Read unexpected signal\n");
> }
> }
> }
>
>
> and a multi-threaded client to test with:
>
> #include <unistd.h>
> #include <pthread.h>
>
> void *f(void *arg)
> {
> sleep(100);
> }
>
> int main()
> {
> pthread_t t[8];
>
> for (int i = 0; i != 8; ++i)
> {
> pthread_create(&t[i], NULL, f, NULL);
> }
> }
>
> I tried to do a bit of debugging and what seems to be happening is
> that
>
> /* From an ancestor pid namespace? */
> if (!task_pid_nr_ns(current, task_active_pid_ns(t))) {
>
> fails inside task_pid_nr_ns because the check for "pid_alive" fails.
>
> This code seems to be called from do_notify_parent and there we
> actually have "tsk != current" (I am assuming both are threads of the
> current process?)
I instrumented the code with a warning and received the following backtrace:
> WARNING: CPU: 0 PID: 777 at kernel/pid.c:501 __task_pid_nr_ns.cold.6+0xc/0x15
> Modules linked in:
> CPU: 0 PID: 777 Comm: sfdclient Not tainted 5.7.0-rc1userns+ #2924
> Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
> RIP: 0010:__task_pid_nr_ns.cold.6+0xc/0x15
> Code: ff 66 90 48 83 ec 08 89 7c 24 04 48 8d 7e 08 48 8d 74 24 04 e8 9a b6 44 00 48 83 c4 08 c3 48 c7 c7 59 9f ac 82 e8 c2 c4 04 00 <0f> 0b e9 3fd
> RSP: 0018:ffffc9000042fbf8 EFLAGS: 00010046
> RAX: 000000000000000c RBX: 0000000000000000 RCX: ffffc9000042faf4
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff81193d29
> RBP: ffffc9000042fc18 R08: 0000000000000000 R09: 0000000000000001
> R10: 000000100f938416 R11: 0000000000000309 R12: ffff8880b941c140
> R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880b941c140
> FS: 0000000000000000(0000) GS:ffff8880bca00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f2e8c0a32e0 CR3: 0000000002e10000 CR4: 00000000000006f0
> Call Trace:
> send_signal+0x1c8/0x310
> do_notify_parent+0x50f/0x550
> release_task.part.21+0x4fd/0x620
> do_exit+0x6f6/0xaf0
> do_group_exit+0x42/0xb0
> get_signal+0x13b/0xbb0
> do_signal+0x2b/0x670
> ? __audit_syscall_exit+0x24d/0x2b0
> ? rcu_read_lock_sched_held+0x4d/0x60
> ? kfree+0x24c/0x2b0
> do_syscall_64+0x176/0x640
> ? trace_hardirqs_off_thunk+0x1a/0x1c
> entry_SYSCALL_64_after_hwframe+0x49/0xb3
The immediate problem is as Christof noticed that "pid_alive(current) == false".
This happens because do_notify_parent is called from the last thread to exit
in a process after that thread has been reaped.
The bigger issue is that do_notify_parent can be called from any
process that manages to wait on a thread of a multi-threaded process
from wait_task_zombie. So any logic based upon current for
do_notify_parent is just nonsense, as current can be pretty much
anything.
So change do_notify_parent to call __send_signal directly.
Inspecting the code it appears this problem has existed since the pid
namespace support started handling this case in 2.6.30. This fix only
backports to 7a0cf094944e ("signal: Correct namespace fixups of si_pid and si_uid")
where the problem logic was moved out of __send_signal and into send_signal.
Cc: stable(a)vger.kernel.org
Fixes: 6588c1e3ff01 ("signals: SI_USER: Masquerade si_pid when crossing pid ns boundary")
Ref: 921cf9f63089 ("signals: protect cinit from unblocked SIG_DFL signals")
Link: https://lore.kernel.org/lkml/20200419201336.GI22017@edge.cmeerw.net/
Reported-by: Christof Meerwald <cmeerw(a)cmeerw.org>
Acked-by: Oleg Nesterov <oleg(a)redhat.com>
Acked-by: Christian Brauner <christian.brauner(a)ubuntu.com>
Signed-off-by: "Eric W. Biederman" <ebiederm(a)xmission.com>
diff --git a/kernel/signal.c b/kernel/signal.c
index e58a6c619824..7938c60e11dd 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1993,8 +1993,12 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN)
sig = 0;
}
+ /*
+ * Send with __send_signal as si_pid and si_uid are in the
+ * parent's namespaces.
+ */
if (valid_signal(sig) && sig)
- __group_send_sig_info(sig, &info, tsk->parent);
+ __send_signal(sig, &info, tsk->parent, PIDTYPE_TGID, false);
__wake_up_parent(tsk, tsk->parent);
spin_unlock_irqrestore(&psig->siglock, flags);
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 61e713bdca3678e84815f2427f7a063fc353a1fc Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm(a)xmission.com>
Date: Mon, 20 Apr 2020 11:41:50 -0500
Subject: [PATCH] signal: Avoid corrupting si_pid and si_uid in
do_notify_parent
Christof Meerwald <cmeerw(a)cmeerw.org> writes:
> Hi,
>
> this is probably related to commit
> 7a0cf094944e2540758b7f957eb6846d5126f535 (signal: Correct namespace
> fixups of si_pid and si_uid).
>
> With a 5.6.5 kernel I am seeing SIGCHLD signals that don't include a
> properly set si_pid field - this seems to happen for multi-threaded
> child processes.
>
> A simple test program (based on the sample from the signalfd man page):
>
> #include <sys/signalfd.h>
> #include <signal.h>
> #include <unistd.h>
> #include <spawn.h>
> #include <stdlib.h>
> #include <stdio.h>
>
> #define handle_error(msg) \
> do { perror(msg); exit(EXIT_FAILURE); } while (0)
>
> int main(int argc, char *argv[])
> {
> sigset_t mask;
> int sfd;
> struct signalfd_siginfo fdsi;
> ssize_t s;
>
> sigemptyset(&mask);
> sigaddset(&mask, SIGCHLD);
>
> if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1)
> handle_error("sigprocmask");
>
> pid_t chldpid;
> char *chldargv[] = { "./sfdclient", NULL };
> posix_spawn(&chldpid, "./sfdclient", NULL, NULL, chldargv, NULL);
>
> sfd = signalfd(-1, &mask, 0);
> if (sfd == -1)
> handle_error("signalfd");
>
> for (;;) {
> s = read(sfd, &fdsi, sizeof(struct signalfd_siginfo));
> if (s != sizeof(struct signalfd_siginfo))
> handle_error("read");
>
> if (fdsi.ssi_signo == SIGCHLD) {
> printf("Got SIGCHLD %d %d %d %d\n",
> fdsi.ssi_status, fdsi.ssi_code,
> fdsi.ssi_uid, fdsi.ssi_pid);
> return 0;
> } else {
> printf("Read unexpected signal\n");
> }
> }
> }
>
>
> and a multi-threaded client to test with:
>
> #include <unistd.h>
> #include <pthread.h>
>
> void *f(void *arg)
> {
> sleep(100);
> }
>
> int main()
> {
> pthread_t t[8];
>
> for (int i = 0; i != 8; ++i)
> {
> pthread_create(&t[i], NULL, f, NULL);
> }
> }
>
> I tried to do a bit of debugging and what seems to be happening is
> that
>
> /* From an ancestor pid namespace? */
> if (!task_pid_nr_ns(current, task_active_pid_ns(t))) {
>
> fails inside task_pid_nr_ns because the check for "pid_alive" fails.
>
> This code seems to be called from do_notify_parent and there we
> actually have "tsk != current" (I am assuming both are threads of the
> current process?)
I instrumented the code with a warning and received the following backtrace:
> WARNING: CPU: 0 PID: 777 at kernel/pid.c:501 __task_pid_nr_ns.cold.6+0xc/0x15
> Modules linked in:
> CPU: 0 PID: 777 Comm: sfdclient Not tainted 5.7.0-rc1userns+ #2924
> Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
> RIP: 0010:__task_pid_nr_ns.cold.6+0xc/0x15
> Code: ff 66 90 48 83 ec 08 89 7c 24 04 48 8d 7e 08 48 8d 74 24 04 e8 9a b6 44 00 48 83 c4 08 c3 48 c7 c7 59 9f ac 82 e8 c2 c4 04 00 <0f> 0b e9 3fd
> RSP: 0018:ffffc9000042fbf8 EFLAGS: 00010046
> RAX: 000000000000000c RBX: 0000000000000000 RCX: ffffc9000042faf4
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff81193d29
> RBP: ffffc9000042fc18 R08: 0000000000000000 R09: 0000000000000001
> R10: 000000100f938416 R11: 0000000000000309 R12: ffff8880b941c140
> R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880b941c140
> FS: 0000000000000000(0000) GS:ffff8880bca00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f2e8c0a32e0 CR3: 0000000002e10000 CR4: 00000000000006f0
> Call Trace:
> send_signal+0x1c8/0x310
> do_notify_parent+0x50f/0x550
> release_task.part.21+0x4fd/0x620
> do_exit+0x6f6/0xaf0
> do_group_exit+0x42/0xb0
> get_signal+0x13b/0xbb0
> do_signal+0x2b/0x670
> ? __audit_syscall_exit+0x24d/0x2b0
> ? rcu_read_lock_sched_held+0x4d/0x60
> ? kfree+0x24c/0x2b0
> do_syscall_64+0x176/0x640
> ? trace_hardirqs_off_thunk+0x1a/0x1c
> entry_SYSCALL_64_after_hwframe+0x49/0xb3
The immediate problem is as Christof noticed that "pid_alive(current) == false".
This happens because do_notify_parent is called from the last thread to exit
in a process after that thread has been reaped.
The bigger issue is that do_notify_parent can be called from any
process that manages to wait on a thread of a multi-threaded process
from wait_task_zombie. So any logic based upon current for
do_notify_parent is just nonsense, as current can be pretty much
anything.
So change do_notify_parent to call __send_signal directly.
Inspecting the code it appears this problem has existed since the pid
namespace support started handling this case in 2.6.30. This fix only
backports to 7a0cf094944e ("signal: Correct namespace fixups of si_pid and si_uid")
where the problem logic was moved out of __send_signal and into send_signal.
Cc: stable(a)vger.kernel.org
Fixes: 6588c1e3ff01 ("signals: SI_USER: Masquerade si_pid when crossing pid ns boundary")
Ref: 921cf9f63089 ("signals: protect cinit from unblocked SIG_DFL signals")
Link: https://lore.kernel.org/lkml/20200419201336.GI22017@edge.cmeerw.net/
Reported-by: Christof Meerwald <cmeerw(a)cmeerw.org>
Acked-by: Oleg Nesterov <oleg(a)redhat.com>
Acked-by: Christian Brauner <christian.brauner(a)ubuntu.com>
Signed-off-by: "Eric W. Biederman" <ebiederm(a)xmission.com>
diff --git a/kernel/signal.c b/kernel/signal.c
index e58a6c619824..7938c60e11dd 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1993,8 +1993,12 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN)
sig = 0;
}
+ /*
+ * Send with __send_signal as si_pid and si_uid are in the
+ * parent's namespaces.
+ */
if (valid_signal(sig) && sig)
- __group_send_sig_info(sig, &info, tsk->parent);
+ __send_signal(sig, &info, tsk->parent, PIDTYPE_TGID, false);
__wake_up_parent(tsk, tsk->parent);
spin_unlock_irqrestore(&psig->siglock, flags);
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 61e713bdca3678e84815f2427f7a063fc353a1fc Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm(a)xmission.com>
Date: Mon, 20 Apr 2020 11:41:50 -0500
Subject: [PATCH] signal: Avoid corrupting si_pid and si_uid in
do_notify_parent
Christof Meerwald <cmeerw(a)cmeerw.org> writes:
> Hi,
>
> this is probably related to commit
> 7a0cf094944e2540758b7f957eb6846d5126f535 (signal: Correct namespace
> fixups of si_pid and si_uid).
>
> With a 5.6.5 kernel I am seeing SIGCHLD signals that don't include a
> properly set si_pid field - this seems to happen for multi-threaded
> child processes.
>
> A simple test program (based on the sample from the signalfd man page):
>
> #include <sys/signalfd.h>
> #include <signal.h>
> #include <unistd.h>
> #include <spawn.h>
> #include <stdlib.h>
> #include <stdio.h>
>
> #define handle_error(msg) \
> do { perror(msg); exit(EXIT_FAILURE); } while (0)
>
> int main(int argc, char *argv[])
> {
> sigset_t mask;
> int sfd;
> struct signalfd_siginfo fdsi;
> ssize_t s;
>
> sigemptyset(&mask);
> sigaddset(&mask, SIGCHLD);
>
> if (sigprocmask(SIG_BLOCK, &mask, NULL) == -1)
> handle_error("sigprocmask");
>
> pid_t chldpid;
> char *chldargv[] = { "./sfdclient", NULL };
> posix_spawn(&chldpid, "./sfdclient", NULL, NULL, chldargv, NULL);
>
> sfd = signalfd(-1, &mask, 0);
> if (sfd == -1)
> handle_error("signalfd");
>
> for (;;) {
> s = read(sfd, &fdsi, sizeof(struct signalfd_siginfo));
> if (s != sizeof(struct signalfd_siginfo))
> handle_error("read");
>
> if (fdsi.ssi_signo == SIGCHLD) {
> printf("Got SIGCHLD %d %d %d %d\n",
> fdsi.ssi_status, fdsi.ssi_code,
> fdsi.ssi_uid, fdsi.ssi_pid);
> return 0;
> } else {
> printf("Read unexpected signal\n");
> }
> }
> }
>
>
> and a multi-threaded client to test with:
>
> #include <unistd.h>
> #include <pthread.h>
>
> void *f(void *arg)
> {
> sleep(100);
> }
>
> int main()
> {
> pthread_t t[8];
>
> for (int i = 0; i != 8; ++i)
> {
> pthread_create(&t[i], NULL, f, NULL);
> }
> }
>
> I tried to do a bit of debugging and what seems to be happening is
> that
>
> /* From an ancestor pid namespace? */
> if (!task_pid_nr_ns(current, task_active_pid_ns(t))) {
>
> fails inside task_pid_nr_ns because the check for "pid_alive" fails.
>
> This code seems to be called from do_notify_parent and there we
> actually have "tsk != current" (I am assuming both are threads of the
> current process?)
I instrumented the code with a warning and received the following backtrace:
> WARNING: CPU: 0 PID: 777 at kernel/pid.c:501 __task_pid_nr_ns.cold.6+0xc/0x15
> Modules linked in:
> CPU: 0 PID: 777 Comm: sfdclient Not tainted 5.7.0-rc1userns+ #2924
> Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
> RIP: 0010:__task_pid_nr_ns.cold.6+0xc/0x15
> Code: ff 66 90 48 83 ec 08 89 7c 24 04 48 8d 7e 08 48 8d 74 24 04 e8 9a b6 44 00 48 83 c4 08 c3 48 c7 c7 59 9f ac 82 e8 c2 c4 04 00 <0f> 0b e9 3fd
> RSP: 0018:ffffc9000042fbf8 EFLAGS: 00010046
> RAX: 000000000000000c RBX: 0000000000000000 RCX: ffffc9000042faf4
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff81193d29
> RBP: ffffc9000042fc18 R08: 0000000000000000 R09: 0000000000000001
> R10: 000000100f938416 R11: 0000000000000309 R12: ffff8880b941c140
> R13: 0000000000000000 R14: 0000000000000000 R15: ffff8880b941c140
> FS: 0000000000000000(0000) GS:ffff8880bca00000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f2e8c0a32e0 CR3: 0000000002e10000 CR4: 00000000000006f0
> Call Trace:
> send_signal+0x1c8/0x310
> do_notify_parent+0x50f/0x550
> release_task.part.21+0x4fd/0x620
> do_exit+0x6f6/0xaf0
> do_group_exit+0x42/0xb0
> get_signal+0x13b/0xbb0
> do_signal+0x2b/0x670
> ? __audit_syscall_exit+0x24d/0x2b0
> ? rcu_read_lock_sched_held+0x4d/0x60
> ? kfree+0x24c/0x2b0
> do_syscall_64+0x176/0x640
> ? trace_hardirqs_off_thunk+0x1a/0x1c
> entry_SYSCALL_64_after_hwframe+0x49/0xb3
The immediate problem is as Christof noticed that "pid_alive(current) == false".
This happens because do_notify_parent is called from the last thread to exit
in a process after that thread has been reaped.
The bigger issue is that do_notify_parent can be called from any
process that manages to wait on a thread of a multi-threaded process
from wait_task_zombie. So any logic based upon current for
do_notify_parent is just nonsense, as current can be pretty much
anything.
So change do_notify_parent to call __send_signal directly.
Inspecting the code it appears this problem has existed since the pid
namespace support started handling this case in 2.6.30. This fix only
backports to 7a0cf094944e ("signal: Correct namespace fixups of si_pid and si_uid")
where the problem logic was moved out of __send_signal and into send_signal.
Cc: stable(a)vger.kernel.org
Fixes: 6588c1e3ff01 ("signals: SI_USER: Masquerade si_pid when crossing pid ns boundary")
Ref: 921cf9f63089 ("signals: protect cinit from unblocked SIG_DFL signals")
Link: https://lore.kernel.org/lkml/20200419201336.GI22017@edge.cmeerw.net/
Reported-by: Christof Meerwald <cmeerw(a)cmeerw.org>
Acked-by: Oleg Nesterov <oleg(a)redhat.com>
Acked-by: Christian Brauner <christian.brauner(a)ubuntu.com>
Signed-off-by: "Eric W. Biederman" <ebiederm(a)xmission.com>
diff --git a/kernel/signal.c b/kernel/signal.c
index e58a6c619824..7938c60e11dd 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1993,8 +1993,12 @@ bool do_notify_parent(struct task_struct *tsk, int sig)
if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN)
sig = 0;
}
+ /*
+ * Send with __send_signal as si_pid and si_uid are in the
+ * parent's namespaces.
+ */
if (valid_signal(sig) && sig)
- __group_send_sig_info(sig, &info, tsk->parent);
+ __send_signal(sig, &info, tsk->parent, PIDTYPE_TGID, false);
__wake_up_parent(tsk, tsk->parent);
spin_unlock_irqrestore(&psig->siglock, flags);
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e5b72e3bc4763152e24bf4b8333bae21cc526c56 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg(a)intel.com>
Date: Fri, 17 Apr 2020 10:08:12 +0300
Subject: [PATCH] iwlwifi: mvm: limit maximum queue appropriately
Due to some hardware issues, queue 31 isn't usable on devices that have
32 queues (7000, 8000, 9000 families), which is correctly reflected in
the configuration and TX queue initialization.
However, the firmware API and queue allocation code assumes that there
are 32 queues, and if something actually attempts to use #31 this leads
to a NULL-pointer dereference since it's not allocated.
Fix this by limiting to 31 in the IWL_MVM_DQA_MAX_DATA_QUEUE, and also
add some code to catch this earlier in the future, if the configuration
changes perhaps.
Cc: stable(a)vger.kernel.org # v4.9+
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
Signed-off-by: Luca Coelho <luciano.coelho(a)intel.com>
Signed-off-by: Kalle Valo <kvalo(a)codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20200417100405.98a79be2db6a.I3a4af6b03b87…
diff --git a/drivers/net/wireless/intel/iwlwifi/fw/api/txq.h b/drivers/net/wireless/intel/iwlwifi/fw/api/txq.h
index 73196cbc7fbe..75d958bab0e3 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/api/txq.h
+++ b/drivers/net/wireless/intel/iwlwifi/fw/api/txq.h
@@ -8,7 +8,7 @@
* Copyright(c) 2007 - 2014 Intel Corporation. All rights reserved.
* Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
* Copyright(c) 2016 - 2017 Intel Deutschland GmbH
- * Copyright(c) 2019 Intel Corporation
+ * Copyright(c) 2019 - 2020 Intel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
@@ -31,7 +31,7 @@
* Copyright(c) 2005 - 2014 Intel Corporation. All rights reserved.
* Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
* Copyright(c) 2016 - 2017 Intel Deutschland GmbH
- * Copyright(c) 2019 Intel Corporation
+ * Copyright(c) 2019 - 2020 Intel Corporation
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -99,7 +99,7 @@ enum iwl_mvm_dqa_txq {
IWL_MVM_DQA_MAX_MGMT_QUEUE = 8,
IWL_MVM_DQA_AP_PROBE_RESP_QUEUE = 9,
IWL_MVM_DQA_MIN_DATA_QUEUE = 10,
- IWL_MVM_DQA_MAX_DATA_QUEUE = 31,
+ IWL_MVM_DQA_MAX_DATA_QUEUE = 30,
};
enum iwl_mvm_tx_fifo {
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
index 64ef3f3ba23b..251d6fbb1da5 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -722,6 +722,11 @@ static int iwl_mvm_find_free_queue(struct iwl_mvm *mvm, u8 sta_id,
lockdep_assert_held(&mvm->mutex);
+ if (WARN(maxq >= mvm->trans->trans_cfg->base_params->num_of_queues,
+ "max queue %d >= num_of_queues (%d)", maxq,
+ mvm->trans->trans_cfg->base_params->num_of_queues))
+ maxq = mvm->trans->trans_cfg->base_params->num_of_queues - 1;
+
/* This should not be hit with new TX path */
if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
return -ENOSPC;
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From e5b72e3bc4763152e24bf4b8333bae21cc526c56 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg(a)intel.com>
Date: Fri, 17 Apr 2020 10:08:12 +0300
Subject: [PATCH] iwlwifi: mvm: limit maximum queue appropriately
Due to some hardware issues, queue 31 isn't usable on devices that have
32 queues (7000, 8000, 9000 families), which is correctly reflected in
the configuration and TX queue initialization.
However, the firmware API and queue allocation code assumes that there
are 32 queues, and if something actually attempts to use #31 this leads
to a NULL-pointer dereference since it's not allocated.
Fix this by limiting to 31 in the IWL_MVM_DQA_MAX_DATA_QUEUE, and also
add some code to catch this earlier in the future, if the configuration
changes perhaps.
Cc: stable(a)vger.kernel.org # v4.9+
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
Signed-off-by: Luca Coelho <luciano.coelho(a)intel.com>
Signed-off-by: Kalle Valo <kvalo(a)codeaurora.org>
Link: https://lore.kernel.org/r/iwlwifi.20200417100405.98a79be2db6a.I3a4af6b03b87…
diff --git a/drivers/net/wireless/intel/iwlwifi/fw/api/txq.h b/drivers/net/wireless/intel/iwlwifi/fw/api/txq.h
index 73196cbc7fbe..75d958bab0e3 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/api/txq.h
+++ b/drivers/net/wireless/intel/iwlwifi/fw/api/txq.h
@@ -8,7 +8,7 @@
* Copyright(c) 2007 - 2014 Intel Corporation. All rights reserved.
* Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
* Copyright(c) 2016 - 2017 Intel Deutschland GmbH
- * Copyright(c) 2019 Intel Corporation
+ * Copyright(c) 2019 - 2020 Intel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
@@ -31,7 +31,7 @@
* Copyright(c) 2005 - 2014 Intel Corporation. All rights reserved.
* Copyright(c) 2013 - 2015 Intel Mobile Communications GmbH
* Copyright(c) 2016 - 2017 Intel Deutschland GmbH
- * Copyright(c) 2019 Intel Corporation
+ * Copyright(c) 2019 - 2020 Intel Corporation
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
@@ -99,7 +99,7 @@ enum iwl_mvm_dqa_txq {
IWL_MVM_DQA_MAX_MGMT_QUEUE = 8,
IWL_MVM_DQA_AP_PROBE_RESP_QUEUE = 9,
IWL_MVM_DQA_MIN_DATA_QUEUE = 10,
- IWL_MVM_DQA_MAX_DATA_QUEUE = 31,
+ IWL_MVM_DQA_MAX_DATA_QUEUE = 30,
};
enum iwl_mvm_tx_fifo {
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
index 64ef3f3ba23b..251d6fbb1da5 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/sta.c
@@ -722,6 +722,11 @@ static int iwl_mvm_find_free_queue(struct iwl_mvm *mvm, u8 sta_id,
lockdep_assert_held(&mvm->mutex);
+ if (WARN(maxq >= mvm->trans->trans_cfg->base_params->num_of_queues,
+ "max queue %d >= num_of_queues (%d)", maxq,
+ mvm->trans->trans_cfg->base_params->num_of_queues))
+ maxq = mvm->trans->trans_cfg->base_params->num_of_queues - 1;
+
/* This should not be hit with new TX path */
if (WARN_ON(iwl_mvm_has_new_tx_api(mvm)))
return -ENOSPC;