[syzbot] [mm?] general protection fault in __hugetlb_zap_begin

[syzbot] [mm?] general protection fault in __hugetlb_zap_begin

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    3a568e3a961b Merge tag 'soc-fixes-6.7-3' of git://git.kern..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=159d9cdd680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=174a257c5ae6b4fd
dashboard link: https://syzkaller.appspot.com/bug?extid=ec9435c038e451be48ff
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14e433eb680000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16808d35680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/70fcba190275/disk-3a568e3a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/65a6a954dd61/vmlinux-3a568e3a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e4d7963284af/bzImage-3a568e3a.xz

The issue was bisected to:

commit bf4916922c60f43efaa329744b3eef539aa6a2b2
Author: Rik van Riel <riel@surriel.com>
Date:   Fri Oct 6 03:59:07 2023 +0000

    hugetlbfs: extend hugetlb_vma_lock to private VMAs

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=17d92743680000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=14392743680000
console output: https://syzkaller.appspot.com/x/log.txt?x=10392743680000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ec9435c038e451be48ff@syzkaller.appspotmail.com
Fixes: bf4916922c60 ("hugetlbfs: extend hugetlb_vma_lock to private VMAs")

general protection fault, probably for non-canonical address 0xdffffc000000001d: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000e8-0x00000000000000ef]
CPU: 1 PID: 5048 Comm: syz-executor261 Not tainted 6.6.0-rc7-syzkaller-00123-g3a568e3a961b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
RIP: 0010:__lock_acquire+0x10d/0x7f70 kernel/locking/lockdep.c:5004
Code: 85 75 18 00 00 83 3d fd 93 2c 0d 00 48 89 9c 24 10 01 00 00 0f 84 f8 0f 00 00 83 3d 5c 8c b2 0b 00 74 34 48 89 d0 48 c1 e8 03 <42> 80 3c 00 00 74 1a 48 89 d7 e8 24 c0 7b 00 48 8b 94 24 80 00 00
RSP: 0018:ffffc90003abf440 EFLAGS: 00010006
RAX: 000000000000001d RBX: 1ffff92000757eac RCX: 0000000000000000
RDX: 00000000000000e8 RSI: 0000000000000000 RDI: 00000000000000e8
RBP: ffffc90003abf708 R08: dffffc0000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1d32d6e R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff88807b34bb80
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbcd77db0d0 CR3: 0000000029b05000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5753
 down_write+0x3a/0x50 kernel/locking/rwsem.c:1573
 __hugetlb_zap_begin+0x2e0/0x380 mm/hugetlb.c:5447
 hugetlb_zap_begin include/linux/hugetlb.h:258 [inline]
 unmap_vmas+0x364/0x5c0 mm/memory.c:1733
 exit_mmap+0x297/0xc50 mm/mmap.c:3230
 __mmput+0x115/0x3c0 kernel/fork.c:1349
 exit_mm+0x21f/0x300 kernel/exit.c:567
 do_exit+0x9af/0x2650 kernel/exit.c:861
 __do_sys_exit kernel/exit.c:991 [inline]
 __se_sys_exit kernel/exit.c:989 [inline]
 __x64_sys_exit+0x40/0x40 kernel/exit.c:989
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fbcd7764af9
Code: Unable to access opcode bytes at 0x7fbcd7764acf.
RSP: 002b:00007ffe3ee5cb58 EFLAGS: 00000246
 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fbcd7764af9
RDX: 00007fbcd779e433 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000011f97 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe3ee5cc7c
R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0x10d/0x7f70 kernel/locking/lockdep.c:5004
Code: 85 75 18 00 00 83 3d fd 93 2c 0d 00 48 89 9c 24 10 01 00 00 0f 84 f8 0f 00 00 83 3d 5c 8c b2 0b 00 74 34 48 89 d0 48 c1 e8 03 <42> 80 3c 00 00 74 1a 48 89 d7 e8 24 c0 7b 00 48 8b 94 24 80 00 00
RSP: 0018:ffffc90003abf440 EFLAGS: 00010006

RAX: 000000000000001d RBX: 1ffff92000757eac RCX: 0000000000000000
RDX: 00000000000000e8 RSI: 0000000000000000 RDI: 00000000000000e8
RBP: ffffc90003abf708 R08: dffffc0000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1d32d6e R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffff88807b34bb80
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbcd77db0d0 CR3: 0000000029b05000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	85 75 18             	test   %esi,0x18(%rbp)
   3:	00 00                	add    %al,(%rax)
   5:	83 3d fd 93 2c 0d 00 	cmpl   $0x0,0xd2c93fd(%rip)        # 0xd2c9409
   c:	48 89 9c 24 10 01 00 	mov    %rbx,0x110(%rsp)
  13:	00
  14:	0f 84 f8 0f 00 00    	je     0x1012
  1a:	83 3d 5c 8c b2 0b 00 	cmpl   $0x0,0xbb28c5c(%rip)        # 0xbb28c7d
  21:	74 34                	je     0x57
  23:	48 89 d0             	mov    %rdx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 00 00       	cmpb   $0x0,(%rax,%r8,1) <-- trapping instruction
  2f:	74 1a                	je     0x4b
  31:	48 89 d7             	mov    %rdx,%rdi
  34:	e8 24 c0 7b 00       	call   0x7bc05d
  39:	48                   	rex.W
  3a:	8b                   	.byte 0x8b
  3b:	94                   	xchg   %eax,%esp
  3c:	24 80                	and    $0x80,%al


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the bug is already fixed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite bug's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the bug is a duplicate of another bug, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [PATCH] Test for 2030579113a1

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [PATCH] Test for 2030579113a1
Author: eadavis@qq.com

please test BUG: corrupted list in ptp_open

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 2dac75696c6d

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 282cd7d24077..6e9762a54b14 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -119,8 +119,13 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 	}
 	bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 	spin_lock_init(&queue->lock);
+	if (mutex_lock_interruptible(&ptp->tsevq_mux)) {
+		kfree(queue);
+		return -ERESTARTSYS;
+	}
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
 	pccontext->private_clkdata = queue;
+	mutex_unlock(&ptp->tsevq_mux);
 
 	/* Debugfs contents */
 	sprintf(debugfsname, "0x%p", queue);
@@ -138,14 +143,19 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 int ptp_release(struct posix_clock_context *pccontext)
 {
 	struct timestamp_event_queue *queue = pccontext->private_clkdata;
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 	unsigned long flags;
 
 	if (queue) {
+		if (mutex_lock_interruptible(&ptp->tsevq_mux)) 
+			return -ERESTARTSYS;
 		debugfs_remove(queue->debugfs_instance);
 		pccontext->private_clkdata = NULL;
 		spin_lock_irqsave(&queue->lock, flags);
 		list_del(&queue->qlist);
 		spin_unlock_irqrestore(&queue->lock, flags);
+		mutex_unlock(&ptp->tsevq_mux);
 		bitmap_free(queue->mask);
 		kfree(queue);
 	}
@@ -585,7 +595,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
 free_event:
 	kfree(event);
 exit:
-	if (result < 0)
-		ptp_release(pccontext);
 	return result;
 }
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 3d1b0a97301c..7930db6ec18d 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -176,6 +176,7 @@ static void ptp_clock_release(struct device *dev)
 
 	ptp_cleanup_pin_groups(ptp);
 	kfree(ptp->vclock_index);
+	mutex_destroy(&ptp->tsevq_mux);
 	mutex_destroy(&ptp->pincfg_mux);
 	mutex_destroy(&ptp->n_vclocks_mux);
 	/* Delete first entry */
@@ -247,6 +248,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	if (!queue)
 		goto no_memory_queue;
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
+	mutex_init(&ptp->tsevq_mux);
 	queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
 	if (!queue->mask)
 		goto no_memory_bitmap;
@@ -356,6 +358,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	if (ptp->kworker)
 		kthread_destroy_worker(ptp->kworker);
 kworker_err:
+	mutex_destroy(&ptp->tsevq_mux);
 	mutex_destroy(&ptp->pincfg_mux);
 	mutex_destroy(&ptp->n_vclocks_mux);
 	bitmap_free(queue->mask);
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 52f87e394aa6..1525bd2059ba 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -44,6 +44,7 @@ struct ptp_clock {
 	struct pps_device *pps_source;
 	long dialed_frequency; /* remembers the frequency adjustment */
 	struct list_head tsevqs; /* timestamp fifo list */
+	struct mutex tsevq_mux; /* one process at a time reading the fifo */
 	struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
 	wait_queue_head_t tsev_wq;
 	int defunct; /* tells readers to go away when clock is being removed */
-- 
2.25.1

Re: [syzbot] [mm?] general protection fault in __hugetlb_zap_begin

[syzbot]

syzbot suspects this issue was fixed by commit:

commit 187da0f8250aa94bd96266096aef6f694e0b4cd2
Author: Mike Kravetz <mike.kravetz@oracle.com>
Date:   Tue Nov 14 01:20:33 2023 +0000

    hugetlb: fix null-ptr-deref in hugetlb_vma_lock_write

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=17f5054de80000
start commit:   9b6de136b5f0 Merge tag 'loongarch-fixes-6.7-1' of git://gi..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=52c9552def2a0fdd
dashboard link: https://syzkaller.appspot.com/bug?extid=ec9435c038e451be48ff
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=150a257ce80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13481ff0e80000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: hugetlb: fix null-ptr-deref in hugetlb_vma_lock_write

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: [syzbot] [PATCH] Test for 2030579113a1

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [PATCH] Test for 2030579113a1
Author: eadavis@qq.com

please test BUG: corrupted list in ptp_open

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 2dac75696c6d

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 282cd7d24077..473b6d992507 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -108,6 +108,7 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 		container_of(pccontext->clk, struct ptp_clock, clock);
 	struct timestamp_event_queue *queue;
 	char debugfsname[32];
+	unsigned long flags;
 
 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 	if (!queue)
@@ -119,7 +120,9 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 	}
 	bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 	spin_lock_init(&queue->lock);
+	spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
+	spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 	pccontext->private_clkdata = queue;
 
 	/* Debugfs contents */
@@ -139,16 +142,16 @@ int ptp_release(struct posix_clock_context *pccontext)
 {
 	struct timestamp_event_queue *queue = pccontext->private_clkdata;
 	unsigned long flags;
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 
-	if (queue) {
-		debugfs_remove(queue->debugfs_instance);
-		pccontext->private_clkdata = NULL;
-		spin_lock_irqsave(&queue->lock, flags);
-		list_del(&queue->qlist);
-		spin_unlock_irqrestore(&queue->lock, flags);
-		bitmap_free(queue->mask);
-		kfree(queue);
-	}
+	debugfs_remove(queue->debugfs_instance);
+	pccontext->private_clkdata = NULL;
+	spin_lock_irqsave(&ptp->tsevqs_lock, flags);
+	list_del(&queue->qlist);
+	spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
+	bitmap_free(queue->mask);
+	kfree(queue);
 	return 0;
 }
 
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 3d1b0a97301c..b901f2910963 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -179,11 +179,11 @@ static void ptp_clock_release(struct device *dev)
 	mutex_destroy(&ptp->pincfg_mux);
 	mutex_destroy(&ptp->n_vclocks_mux);
 	/* Delete first entry */
+	spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 	tsevq = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,
 				 qlist);
-	spin_lock_irqsave(&tsevq->lock, flags);
 	list_del(&tsevq->qlist);
-	spin_unlock_irqrestore(&tsevq->lock, flags);
+	spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 	bitmap_free(tsevq->mask);
 	kfree(tsevq);
 	debugfs_remove(ptp->debugfs_root);
@@ -247,6 +247,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	if (!queue)
 		goto no_memory_queue;
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
+	spin_lock_init(&ptp->tsevqs_lock);
 	queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
 	if (!queue->mask)
 		goto no_memory_bitmap;
@@ -407,6 +408,7 @@ void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
 {
 	struct timestamp_event_queue *tsevq;
 	struct pps_event_time evt;
+	unsigned long flags;
 
 	switch (event->type) {
 
@@ -415,10 +417,12 @@ void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
 
 	case PTP_CLOCK_EXTTS:
 		/* Enqueue timestamp on selected queues */
+		spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 		list_for_each_entry(tsevq, &ptp->tsevqs, qlist) {
 			if (test_bit((unsigned int)event->index, tsevq->mask))
 				enqueue_external_timestamp(tsevq, event);
 		}
+		spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 		wake_up_interruptible(&ptp->tsev_wq);
 		break;
 
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 52f87e394aa6..35fde0a05746 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -44,6 +44,7 @@ struct ptp_clock {
 	struct pps_device *pps_source;
 	long dialed_frequency; /* remembers the frequency adjustment */
 	struct list_head tsevqs; /* timestamp fifo list */
+	spinlock_t tsevqs_lock; /* protects tsevqs from concurrent access */
 	struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
 	wait_queue_head_t tsev_wq;
 	int defunct; /* tells readers to go away when clock is being removed */
diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 473b6d992507..3f7a74788802 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -588,7 +588,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
 free_event:
 	kfree(event);
 exit:
-	if (result < 0)
-		ptp_release(pccontext);
 	return result;
 }
-- 
2.25.1

Re: [syzbot] [PATCH] Test for 2030579113a1

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [PATCH] Test for 2030579113a1
Author: eadavis@qq.com

please test BUG: corrupted list in ptp_open

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 2dac75696c6d

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 282cd7d24077..473b6d992507 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -108,6 +108,7 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 		container_of(pccontext->clk, struct ptp_clock, clock);
 	struct timestamp_event_queue *queue;
 	char debugfsname[32];
+	unsigned long flags;
 
 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 	if (!queue)
@@ -119,7 +120,9 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 	}
 	bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 	spin_lock_init(&queue->lock);
+	spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
+	spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 	pccontext->private_clkdata = queue;
 
 	/* Debugfs contents */
@@ -139,16 +142,16 @@ int ptp_release(struct posix_clock_context *pccontext)
 {
 	struct timestamp_event_queue *queue = pccontext->private_clkdata;
 	unsigned long flags;
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 
-	if (queue) {
-		debugfs_remove(queue->debugfs_instance);
-		pccontext->private_clkdata = NULL;
-		spin_lock_irqsave(&queue->lock, flags);
-		list_del(&queue->qlist);
-		spin_unlock_irqrestore(&queue->lock, flags);
-		bitmap_free(queue->mask);
-		kfree(queue);
-	}
+	debugfs_remove(queue->debugfs_instance);
+	pccontext->private_clkdata = NULL;
+	spin_lock_irqsave(&ptp->tsevqs_lock, flags);
+	list_del(&queue->qlist);
+	spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
+	bitmap_free(queue->mask);
+	kfree(queue);
 	return 0;
 }
 
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 3d1b0a97301c..b901f2910963 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -179,11 +179,11 @@ static void ptp_clock_release(struct device *dev)
 	mutex_destroy(&ptp->pincfg_mux);
 	mutex_destroy(&ptp->n_vclocks_mux);
 	/* Delete first entry */
+	spin_lock_irqsave(&tsevq->lock, flags);
 	tsevq = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,
 				 qlist);
-	spin_lock_irqsave(&tsevq->lock, flags);
 	list_del(&tsevq->qlist);
-	spin_unlock_irqrestore(&tsevq->lock, flags);
+	spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 	bitmap_free(tsevq->mask);
 	kfree(tsevq);
 	debugfs_remove(ptp->debugfs_root);
@@ -247,6 +247,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	if (!queue)
 		goto no_memory_queue;
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
+	spin_lock_init(&ptp->tsevqs_lock);
 	queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
 	if (!queue->mask)
 		goto no_memory_bitmap;
@@ -407,6 +408,7 @@ void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
 {
 	struct timestamp_event_queue *tsevq;
 	struct pps_event_time evt;
+	unsigned long flags;
 
 	switch (event->type) {
 
@@ -415,10 +417,12 @@ void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
 
 	case PTP_CLOCK_EXTTS:
 		/* Enqueue timestamp on selected queues */
+		spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 		list_for_each_entry(tsevq, &ptp->tsevqs, qlist) {
 			if (test_bit((unsigned int)event->index, tsevq->mask))
 				enqueue_external_timestamp(tsevq, event);
 		}
+		spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 		wake_up_interruptible(&ptp->tsev_wq);
 		break;
 
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 52f87e394aa6..35fde0a05746 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -44,6 +44,7 @@ struct ptp_clock {
 	struct pps_device *pps_source;
 	long dialed_frequency; /* remembers the frequency adjustment */
 	struct list_head tsevqs; /* timestamp fifo list */
+	spinlock_t tsevqs_lock; /* protects tsevqs from concurrent access */
 	struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
 	wait_queue_head_t tsev_wq;
 	int defunct; /* tells readers to go away when clock is being removed */
diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 473b6d992507..3f7a74788802 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -588,7 +588,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
 free_event:
 	kfree(event);
 exit:
-	if (result < 0)
-		ptp_release(pccontext);
 	return result;
 }
-- 
2.25.1

Re: [syzbot] [PATCH] Test for 2030579113a1

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [PATCH] Test for 2030579113a1
Author: eadavis@qq.com

please test BUG: corrupted list in ptp_open

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 2dac75696c6d

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 282cd7d24077..3f7a74788802 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -108,6 +108,7 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 		container_of(pccontext->clk, struct ptp_clock, clock);
 	struct timestamp_event_queue *queue;
 	char debugfsname[32];
+	unsigned long flags;
 
 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 	if (!queue)
@@ -119,7 +120,9 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 	}
 	bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 	spin_lock_init(&queue->lock);
+	spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
+	spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 	pccontext->private_clkdata = queue;
 
 	/* Debugfs contents */
@@ -139,16 +142,16 @@ int ptp_release(struct posix_clock_context *pccontext)
 {
 	struct timestamp_event_queue *queue = pccontext->private_clkdata;
 	unsigned long flags;
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 
-	if (queue) {
-		debugfs_remove(queue->debugfs_instance);
-		pccontext->private_clkdata = NULL;
-		spin_lock_irqsave(&queue->lock, flags);
-		list_del(&queue->qlist);
-		spin_unlock_irqrestore(&queue->lock, flags);
-		bitmap_free(queue->mask);
-		kfree(queue);
-	}
+	debugfs_remove(queue->debugfs_instance);
+	pccontext->private_clkdata = NULL;
+	spin_lock_irqsave(&ptp->tsevqs_lock, flags);
+	list_del(&queue->qlist);
+	spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
+	bitmap_free(queue->mask);
+	kfree(queue);
 	return 0;
 }
 
@@ -585,7 +588,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
 free_event:
 	kfree(event);
 exit:
-	if (result < 0)
-		ptp_release(pccontext);
 	return result;
 }
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 3d1b0a97301c..41b68568811a 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -247,6 +247,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	if (!queue)
 		goto no_memory_queue;
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
+	spin_lock_init(&ptp->tsevqs_lock);
 	queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
 	if (!queue->mask)
 		goto no_memory_bitmap;
@@ -407,6 +408,7 @@ void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
 {
 	struct timestamp_event_queue *tsevq;
 	struct pps_event_time evt;
+	unsigned long flags;
 
 	switch (event->type) {
 
@@ -415,10 +417,12 @@ void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
 
 	case PTP_CLOCK_EXTTS:
 		/* Enqueue timestamp on selected queues */
+		spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 		list_for_each_entry(tsevq, &ptp->tsevqs, qlist) {
 			if (test_bit((unsigned int)event->index, tsevq->mask))
 				enqueue_external_timestamp(tsevq, event);
 		}
+		spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 		wake_up_interruptible(&ptp->tsev_wq);
 		break;
 
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 52f87e394aa6..35fde0a05746 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -44,6 +44,7 @@ struct ptp_clock {
 	struct pps_device *pps_source;
 	long dialed_frequency; /* remembers the frequency adjustment */
 	struct list_head tsevqs; /* timestamp fifo list */
+	spinlock_t tsevqs_lock; /* protects tsevqs from concurrent access */
 	struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
 	wait_queue_head_t tsev_wq;
 	int defunct; /* tells readers to go away when clock is being removed */
-- 
2.25.1

Re: [syzbot] [PATCH] Test for 2030579113a1

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [PATCH] Test for 2030579113a1
Author: eadavis@qq.com

please test BUG: corrupted list in ptp_open

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 2dac75696c6d

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 282cd7d24077..31594f40a21e 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -108,6 +108,7 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 		container_of(pccontext->clk, struct ptp_clock, clock);
 	struct timestamp_event_queue *queue;
 	char debugfsname[32];
+	unsigned long flags;
 
 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 	if (!queue)
@@ -119,8 +120,10 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 	}
 	bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 	spin_lock_init(&queue->lock);
+	spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
 	pccontext->private_clkdata = queue;
+	spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 
 	/* Debugfs contents */
 	sprintf(debugfsname, "0x%p", queue);
@@ -139,13 +142,15 @@ int ptp_release(struct posix_clock_context *pccontext)
 {
 	struct timestamp_event_queue *queue = pccontext->private_clkdata;
 	unsigned long flags;
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 
 	if (queue) {
 		debugfs_remove(queue->debugfs_instance);
+		spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 		pccontext->private_clkdata = NULL;
-		spin_lock_irqsave(&queue->lock, flags);
 		list_del(&queue->qlist);
-		spin_unlock_irqrestore(&queue->lock, flags);
+		spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 		bitmap_free(queue->mask);
 		kfree(queue);
 	}
@@ -585,7 +590,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
 free_event:
 	kfree(event);
 exit:
-	if (result < 0)
-		ptp_release(pccontext);
 	return result;
 }
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 3d1b0a97301c..ea82648ad557 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -247,6 +247,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	if (!queue)
 		goto no_memory_queue;
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
+	spin_lock_init(&ptp->tsevqs_lock);
 	queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
 	if (!queue->mask)
 		goto no_memory_bitmap;
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 52f87e394aa6..63af246f17eb 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -44,6 +44,7 @@ struct ptp_clock {
 	struct pps_device *pps_source;
 	long dialed_frequency; /* remembers the frequency adjustment */
 	struct list_head tsevqs; /* timestamp fifo list */
+	spinlock_t tsevqs_lock; /* one process at a time writing the timestamp fifo list*/
 	struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
 	wait_queue_head_t tsev_wq;
 	int defunct; /* tells readers to go away when clock is being removed */
-- 
2.25.1

Re: [syzbot] [PATCH] Test for 2030579113a1

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [PATCH] Test for 2030579113a1
Author: eadavis@qq.com

please test BUG: corrupted list in ptp_open

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 2dac75696c6d

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 282cd7d24077..eb4015ae93a2 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -108,6 +108,7 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 		container_of(pccontext->clk, struct ptp_clock, clock);
 	struct timestamp_event_queue *queue;
 	char debugfsname[32];
+	unsigned long flags;
 
 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 	if (!queue)
@@ -119,8 +120,10 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 	}
 	bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 	spin_lock_init(&queue->lock);
+	spin_lock_irqsave(&ptp->tsevq_lock, flags);
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
 	pccontext->private_clkdata = queue;
+	spin_unlock_irqrestore(&ptp->tsevq_lock, flags);
 
 	/* Debugfs contents */
 	sprintf(debugfsname, "0x%p", queue);
@@ -139,13 +142,15 @@ int ptp_release(struct posix_clock_context *pccontext)
 {
 	struct timestamp_event_queue *queue = pccontext->private_clkdata;
 	unsigned long flags;
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 
 	if (queue) {
 		debugfs_remove(queue->debugfs_instance);
+		spin_lock_irqsave(&ptp->tsevq_lock, flags);
 		pccontext->private_clkdata = NULL;
-		spin_lock_irqsave(&queue->lock, flags);
 		list_del(&queue->qlist);
-		spin_unlock_irqrestore(&queue->lock, flags);
+		spin_unlock_irqrestore(&ptp->tsevq_lock, flags);
 		bitmap_free(queue->mask);
 		kfree(queue);
 	}
@@ -585,7 +590,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
 free_event:
 	kfree(event);
 exit:
-	if (result < 0)
-		ptp_release(pccontext);
 	return result;
 }
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 3d1b0a97301c..d813bf25dffc 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -247,6 +247,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	if (!queue)
 		goto no_memory_queue;
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
+	spin_lock_init(&ptp->tsevq_lock);
 	queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
 	if (!queue->mask)
 		goto no_memory_bitmap;
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 52f87e394aa6..63af246f17eb 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -44,6 +44,7 @@ struct ptp_clock {
 	struct pps_device *pps_source;
 	long dialed_frequency; /* remembers the frequency adjustment */
 	struct list_head tsevqs; /* timestamp fifo list */
+	spinlock_t tsevqs_lock; /* one process at a time writing the timestamp fifo list*/
 	struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
 	wait_queue_head_t tsev_wq;
 	int defunct; /* tells readers to go away when clock is being removed */
-- 
2.25.1

Re: [syzbot] [PATCH] Test for 2030579113a1

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [PATCH] Test for 2030579113a1
Author: eadavis@qq.com

please test BUG: corrupted list in ptp_open

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 2dac75696c6d

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 282cd7d24077..ba035d6c81ae 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -119,8 +119,13 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 	}
 	bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 	spin_lock_init(&queue->lock);
+	if (mutex_lock_interruptible(&ptp->tsevq_mux)) {
+		kfree(queue);
+		return -ERESTARTSYS;
+	}
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
 	pccontext->private_clkdata = queue;
+	mutex_unlock(&ptp->tsevq_mux);
 
 	/* Debugfs contents */
 	sprintf(debugfsname, "0x%p", queue);
@@ -138,14 +143,16 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 int ptp_release(struct posix_clock_context *pccontext)
 {
 	struct timestamp_event_queue *queue = pccontext->private_clkdata;
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 	unsigned long flags;
 
 	if (queue) {
+		mutex_lock(&ptp->tsevq_mux);
 		debugfs_remove(queue->debugfs_instance);
 		pccontext->private_clkdata = NULL;
-		spin_lock_irqsave(&queue->lock, flags);
 		list_del(&queue->qlist);
-		spin_unlock_irqrestore(&queue->lock, flags);
+		mutex_unlock(&ptp->tsevq_mux);
 		bitmap_free(queue->mask);
 		kfree(queue);
 	}
@@ -585,7 +592,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
 free_event:
 	kfree(event);
 exit:
-	if (result < 0)
-		ptp_release(pccontext);
 	return result;
 }
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 3d1b0a97301c..7930db6ec18d 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -176,6 +176,7 @@ static void ptp_clock_release(struct device *dev)
 
 	ptp_cleanup_pin_groups(ptp);
 	kfree(ptp->vclock_index);
+	mutex_destroy(&ptp->tsevq_mux);
 	mutex_destroy(&ptp->pincfg_mux);
 	mutex_destroy(&ptp->n_vclocks_mux);
 	/* Delete first entry */
@@ -247,6 +248,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	if (!queue)
 		goto no_memory_queue;
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
+	mutex_init(&ptp->tsevq_mux);
 	queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
 	if (!queue->mask)
 		goto no_memory_bitmap;
@@ -356,6 +358,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	if (ptp->kworker)
 		kthread_destroy_worker(ptp->kworker);
 kworker_err:
+	mutex_destroy(&ptp->tsevq_mux);
 	mutex_destroy(&ptp->pincfg_mux);
 	mutex_destroy(&ptp->n_vclocks_mux);
 	bitmap_free(queue->mask);
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 52f87e394aa6..7d82960fd946 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -44,6 +44,7 @@ struct ptp_clock {
 	struct pps_device *pps_source;
 	long dialed_frequency; /* remembers the frequency adjustment */
 	struct list_head tsevqs; /* timestamp fifo list */
+	struct mutex tsevq_mux; /* one process at a time writing the timestamp fifo list */
 	struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
 	wait_queue_head_t tsev_wq;
 	int defunct; /* tells readers to go away when clock is being removed */
-- 
2.25.1

Re: [syzbot] [PATCH] Test for 2030579113a1

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [PATCH] Test for 2030579113a1
Author: eadavis@qq.com

please test BUG: corrupted list in ptp_open

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git 2dac75696c6d

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 282cd7d24077..6e9762a54b14 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -119,8 +119,13 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 	}
 	bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 	spin_lock_init(&queue->lock);
+	if (mutex_lock_interruptible(&ptp->tsevq_mux)) {
+		kfree(queue);
+		return -ERESTARTSYS;
+	}
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
 	pccontext->private_clkdata = queue;
+	mutex_unlock(&ptp->tsevq_mux);
 
 	/* Debugfs contents */
 	sprintf(debugfsname, "0x%p", queue);
@@ -138,14 +143,19 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 int ptp_release(struct posix_clock_context *pccontext)
 {
 	struct timestamp_event_queue *queue = pccontext->private_clkdata;
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 	unsigned long flags;
 
 	if (queue) {
+		if (mutex_lock_interruptible(&ptp->tsevq_mux)) 
+			return -ERESTARTSYS;
 		debugfs_remove(queue->debugfs_instance);
 		pccontext->private_clkdata = NULL;
 		spin_lock_irqsave(&queue->lock, flags);
 		list_del(&queue->qlist);
 		spin_unlock_irqrestore(&queue->lock, flags);
+		mutex_unlock(&ptp->tsevq_mux);
 		bitmap_free(queue->mask);
 		kfree(queue);
 	}
@@ -585,7 +595,5 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
 free_event:
 	kfree(event);
 exit:
-	if (result < 0)
-		ptp_release(pccontext);
 	return result;
 }
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 3d1b0a97301c..7930db6ec18d 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -176,6 +176,7 @@ static void ptp_clock_release(struct device *dev)
 
 	ptp_cleanup_pin_groups(ptp);
 	kfree(ptp->vclock_index);
+	mutex_destroy(&ptp->tsevq_mux);
 	mutex_destroy(&ptp->pincfg_mux);
 	mutex_destroy(&ptp->n_vclocks_mux);
 	/* Delete first entry */
@@ -247,6 +248,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	if (!queue)
 		goto no_memory_queue;
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
+	mutex_init(&ptp->tsevq_mux);
 	queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
 	if (!queue->mask)
 		goto no_memory_bitmap;
@@ -356,6 +358,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	if (ptp->kworker)
 		kthread_destroy_worker(ptp->kworker);
 kworker_err:
+	mutex_destroy(&ptp->tsevq_mux);
 	mutex_destroy(&ptp->pincfg_mux);
 	mutex_destroy(&ptp->n_vclocks_mux);
 	bitmap_free(queue->mask);
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 52f87e394aa6..1525bd2059ba 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -44,6 +44,7 @@ struct ptp_clock {
 	struct pps_device *pps_source;
 	long dialed_frequency; /* remembers the frequency adjustment */
 	struct list_head tsevqs; /* timestamp fifo list */
+	struct mutex tsevq_mux; /* one process at a time reading the fifo */
 	struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
 	wait_queue_head_t tsev_wq;
 	int defunct; /* tells readers to go away when clock is being removed */
-- 
2.25.1