* [syzbot] [kernel?] WARNING in its_msi_teardown
@ 2026-07-29 0:08 syzbot
2026-07-29 8:11 ` Forwarded: " syzbot
2026-07-29 9:29 ` Marc Zyngier
0 siblings, 2 replies; 3+ messages in thread
From: syzbot @ 2026-07-29 0:08 UTC (permalink / raw)
To: linux-arm-kernel, linux-kernel, maz, syzkaller-bugs, tglx
Hello,
syzbot found the following issue on:
HEAD commit: b66b0005b6ce Merge branches 'for-next/fixes' and 'for-next..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=15f7d746580000
kernel config: https://syzkaller.appspot.com/x/.config?x=72c97575381cec47
dashboard link: https://syzkaller.appspot.com/bug?extid=229d761b8a110e6de517
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1667e09e580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17525fde580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63e3226301fe/disk-b66b0005.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b268844cbd22/vmlinux-b66b0005.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9440dfc93d1e/Image-b66b0005.gz.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+229d761b8a110e6de517@syzkaller.appspotmail.com
el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
------------[ cut here ]------------
WARNING: drivers/irqchip/irq-gic-v3-its.c:2251 at its_lpi_free drivers/irqchip/irq-gic-v3-its.c:2251 [inline], CPU#0: syz.0.18/4916
WARNING: drivers/irqchip/irq-gic-v3-its.c:2251 at its_msi_teardown+0x3a4/0x424 drivers/irqchip/irq-gic-v3-its.c:3644, CPU#0: syz.0.18/4916
Modules linked in:
CPU: 0 UID: 0 PID: 4916 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : its_lpi_free drivers/irqchip/irq-gic-v3-its.c:2251 [inline]
pc : its_msi_teardown+0x3a4/0x424 drivers/irqchip/irq-gic-v3-its.c:3644
lr : its_lpi_free drivers/irqchip/irq-gic-v3-its.c:2251 [inline]
lr : its_msi_teardown+0x3a4/0x424 drivers/irqchip/irq-gic-v3-its.c:3644
sp : ffff800098017560
x29: ffff8000980175f0 x28: ffff0000cfc75930 x27: 1fffe00019f8eb26
x26: 1fffe00019f8eb22 x25: ffff0000c13e1000 x24: dfff800000000000
x23: ffff700013002eac x22: 00000000fffffff4 x21: ffff800098017580
x20: ffff0000c1e07ce0 x19: ffff0000cfc75900 x18: 00000000ffffffff
x17: 70202c31206c6176 x16: 0000000000000001 x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000003 x9 : 0000000000000000
x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 00000000ffffffff x4 : 0000000000000cc0 x3 : ffff800081ba1c7c
x2 : 00000000fffffff4 x1 : ffff0000cfb10000 x0 : 0000000000000000
Call trace:
its_lpi_free drivers/irqchip/irq-gic-v3-its.c:2251 [inline] (P)
its_msi_teardown+0x3a4/0x424 drivers/irqchip/irq-gic-v3-its.c:3644 (P)
its_msi_teardown+0xa0/0xb8 drivers/irqchip/irq-gic-its-msi-parent.c:249
msi_remove_device_irq_domain+0x16c/0x27c kernel/irq/msi.c:1127
msi_device_data_release+0x38/0x9c kernel/irq/msi.c:293
dr_node_release+0x4c/0x5c drivers/base/devres.c:122
release_nodes+0xac/0x108 drivers/base/devres.c:546
devres_release_all+0x138/0x1a4 drivers/base/devres.c:576
device_unbind_cleanup+0x80/0x1c8 drivers/base/dd.c:597
__device_release_driver drivers/base/dd.c:1354 [inline]
device_release_driver_internal+0x19c/0x20c drivers/base/dd.c:1372
device_release_driver+0x28/0x38 drivers/base/dd.c:1395
pci_stop_dev drivers/pci/remove.c:27 [inline]
pci_stop_bus_device+0x108/0x14c drivers/pci/remove.c:93
pci_stop_and_remove_bus_device+0x84/0xd0 drivers/pci/remove.c:128
pci_stop_and_remove_bus_device_locked+0x24/0x38 drivers/pci/remove.c:136
remove_store+0xdc/0x148 drivers/pci/pci-sysfs.c:523
dev_attr_store+0x6c/0x90 drivers/base/core.c:2505
sysfs_kf_write+0xe0/0x108 fs/sysfs/file.c:145
kernfs_fop_write_iter+0x260/0x3b8 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x51c/0xa0c fs/read_write.c:687
ksys_write+0x12c/0x228 fs/read_write.c:739
__do_sys_write fs/read_write.c:750 [inline]
__se_sys_write fs/read_write.c:747 [inline]
__arm64_sys_write+0x7c/0x90 fs/read_write.c:747
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
irq event stamp: 1608
hardirqs last enabled at (1607): [<ffff8000868e3f4c>] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:507 [inline]
hardirqs last enabled at (1607): [<ffff8000868e3f4c>] arm64_exit_to_kernel_mode+0x80/0x94 arch/arm64/kernel/entry-common.c:62
hardirqs last disabled at (1608): [<ffff8000868dfe78>] el1_brk64+0x20/0x54 arch/arm64/kernel/entry-common.c:425
softirqs last enabled at (1528): [<ffff800084c10fac>] __alloc_skb+0x1c0/0x610 net/core/skbuff.c:698
softirqs last disabled at (1526): [<ffff800084c10f94>] local_bh_disable include/linux/bottom_half.h:20 [inline]
softirqs last disabled at (1526): [<ffff800084c10f94>] __alloc_skb+0x1a8/0x610 net/core/skbuff.c:697
---[ end trace 0000000000000000 ]---
pci 0000:00:01.0: [1af4:1005] type 00 class 0x00ff00 conventional PCI endpoint
pci 0000:00:01.0: BAR 0 [io 0x1000-0x101f]
pci 0000:00:01.0: BAR 1 [mem 0x10110080-0x101100bf]
pci 0000:00:01.0: BAR 1 [mem 0x10110080-0x101100bf]: assigned
pci 0000:00:01.0: BAR 0 [io 0x1000-0x101f]: assigned
virtio-pci 0000:00:01.0: virtio_pci: leaving for legacy driver
---
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.
If the report is already addressed, 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 report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
^ permalink raw reply [flat|nested] 3+ messages in thread
* Forwarded: Re: [syzbot] [kernel?] WARNING in its_msi_teardown
2026-07-29 0:08 [syzbot] [kernel?] WARNING in its_msi_teardown syzbot
@ 2026-07-29 8:11 ` syzbot
2026-07-29 9:29 ` Marc Zyngier
1 sibling, 0 replies; 3+ messages in thread
From: syzbot @ 2026-07-29 8:11 UTC (permalink / raw)
To: linux-kernel, syzkaller-bugs
For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.
***
Subject: Re: [syzbot] [kernel?] WARNING in its_msi_teardown
Author: rihyeon8648@gmail.com
#syz test
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 6f5811aae59c..f324d3df56c0 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -2108,11 +2108,15 @@ static struct lpi_range *mk_lpi_range(u32 base, u32 span)
{
struct lpi_range *range;
- range = kmalloc_obj(*range);
- if (range) {
- range->base_id = base;
- range->span = span;
- }
+ /*
+ * Handing a range back is not allowed to fail: the callers of
+ * free_lpi_range() have no way of reporting an error, and losing the
+ * range here would leak the LPIs for good. This is a small, order-0
+ * request and lpi_range_lock is a mutex, so the context is sleepable.
+ */
+ range = kmalloc_obj(*range, GFP_KERNEL | __GFP_NOFAIL);
+ range->base_id = base;
+ range->span = span;
return range;
}
@@ -2158,13 +2162,11 @@ static void merge_lpi_ranges(struct lpi_range *a, struct lpi_range *b)
kfree(a);
}
-static int free_lpi_range(u32 base, u32 nr_lpis)
+static void free_lpi_range(u32 base, u32 nr_lpis)
{
struct lpi_range *new, *old;
new = mk_lpi_range(base, nr_lpis);
- if (!new)
- return -ENOMEM;
mutex_lock(&lpi_range_lock);
@@ -2188,14 +2190,12 @@ static int free_lpi_range(u32 base, u32 nr_lpis)
merge_lpi_ranges(new, list_next_entry(new, entry));
mutex_unlock(&lpi_range_lock);
- return 0;
}
-static int __init its_lpi_init(u32 id_bits)
+static void __init its_lpi_init(u32 id_bits)
{
u32 lpis = (1UL << id_bits) - 8192;
u32 numlpis;
- int err;
numlpis = 1UL << GICD_TYPER_NUM_LPIS(gic_rdists->gicd_typer);
@@ -2209,9 +2209,8 @@ static int __init its_lpi_init(u32 id_bits)
* Initializing the allocator is just the same as freeing the
* full range of LPIs.
*/
- err = free_lpi_range(8192, lpis);
+ free_lpi_range(8192, lpis);
pr_debug("ITS: Allocator initialized for %u LPIs\n", lpis);
- return err;
}
static unsigned long *its_lpi_alloc(int nr_irqs, u32 *base, int *nr_ids)
@@ -2248,7 +2247,7 @@ static unsigned long *its_lpi_alloc(int nr_irqs, u32 *base, int *nr_ids)
static void its_lpi_free(unsigned long *bitmap, u32 base, u32 nr_ids)
{
- WARN_ON(free_lpi_range(base, nr_ids));
+ free_lpi_range(base, nr_ids);
bitmap_free(bitmap);
}
@@ -2349,7 +2348,9 @@ static int __init its_setup_lpi_prop_table(void)
pr_info("GICv3: using LPI property table @%pa\n",
&gic_rdists->prop_table_pa);
- return its_lpi_init(lpi_id_bits);
+ its_lpi_init(lpi_id_bits);
+
+ return 0;
}
static const char *its_base_type_string[] = {
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [syzbot] [kernel?] WARNING in its_msi_teardown
2026-07-29 0:08 [syzbot] [kernel?] WARNING in its_msi_teardown syzbot
2026-07-29 8:11 ` Forwarded: " syzbot
@ 2026-07-29 9:29 ` Marc Zyngier
1 sibling, 0 replies; 3+ messages in thread
From: Marc Zyngier @ 2026-07-29 9:29 UTC (permalink / raw)
To: syzbot; +Cc: linux-arm-kernel, linux-kernel, syzkaller-bugs, tglx
On Wed, 29 Jul 2026 01:08:31 +0100,
syzbot <syzbot+229d761b8a110e6de517@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: b66b0005b6ce Merge branches 'for-next/fixes' and 'for-next..
> git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
> console output: https://syzkaller.appspot.com/x/log.txt?x=15f7d746580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=72c97575381cec47
> dashboard link: https://syzkaller.appspot.com/bug?extid=229d761b8a110e6de517
> compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
> userspace arch: arm64
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1667e09e580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17525fde580000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/63e3226301fe/disk-b66b0005.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/b268844cbd22/vmlinux-b66b0005.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/9440dfc93d1e/Image-b66b0005.gz.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+229d761b8a110e6de517@syzkaller.appspotmail.com
>
> el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
> do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
> el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736
> el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755
> el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594
> ------------[ cut here ]------------
> WARNING: drivers/irqchip/irq-gic-v3-its.c:2251 at its_lpi_free drivers/irqchip/irq-gic-v3-its.c:2251 [inline], CPU#0: syz.0.18/4916
> WARNING: drivers/irqchip/irq-gic-v3-its.c:2251 at its_msi_teardown+0x3a4/0x424 drivers/irqchip/irq-gic-v3-its.c:3644, CPU#0: syz.0.18/4916
> Modules linked in:
> CPU: 0 UID: 0 PID: 4916 Comm: syz.0.18 Not tainted syzkaller #0 PREEMPT
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/02/2026
> pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
> pc : its_lpi_free drivers/irqchip/irq-gic-v3-its.c:2251 [inline]
> pc : its_msi_teardown+0x3a4/0x424 drivers/irqchip/irq-gic-v3-its.c:3644
> lr : its_lpi_free drivers/irqchip/irq-gic-v3-its.c:2251 [inline]
> lr : its_msi_teardown+0x3a4/0x424 drivers/irqchip/irq-gic-v3-its.c:3644
> sp : ffff800098017560
> x29: ffff8000980175f0 x28: ffff0000cfc75930 x27: 1fffe00019f8eb26
> x26: 1fffe00019f8eb22 x25: ffff0000c13e1000 x24: dfff800000000000
> x23: ffff700013002eac x22: 00000000fffffff4 x21: ffff800098017580
> x20: ffff0000c1e07ce0 x19: ffff0000cfc75900 x18: 00000000ffffffff
> x17: 70202c31206c6176 x16: 0000000000000001 x15: 0000000000000000
> x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000000
> x11: 0000000000000000 x10: 0000000000000003 x9 : 0000000000000000
> x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000
> x5 : 00000000ffffffff x4 : 0000000000000cc0 x3 : ffff800081ba1c7c
> x2 : 00000000fffffff4 x1 : ffff0000cfb10000 x0 : 0000000000000000
> Call trace:
> its_lpi_free drivers/irqchip/irq-gic-v3-its.c:2251 [inline] (P)
> its_msi_teardown+0x3a4/0x424 drivers/irqchip/irq-gic-v3-its.c:3644 (P)
> its_msi_teardown+0xa0/0xb8 drivers/irqchip/irq-gic-its-msi-parent.c:249
That's an allocation failure, caused by a fault injection. We end-up
leaking LPIs, but there isn't much we can do about that if we can't
allocate the correct tracking structure.
So yes, we WARN() about this, and carry on.
M.
--
Without deviation from the norm, progress is not possible.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-07-29 9:29 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-07-29 0:08 [syzbot] [kernel?] WARNING in its_msi_teardown syzbot
2026-07-29 8:11 ` Forwarded: " syzbot
2026-07-29 9:29 ` Marc Zyngier
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox