Syzkaller reports warning in ext4_set_page_dirty() in 5.10 and 5.15
stable releases. It happens because invalidate_inode_page() frees pages
that are needed for the system. To fix this we need to add additional
checks to the function. page_mapped() checks if a page exists in the
page tables, but this is not enough. The page can be used in other places:
https://elixir.bootlin.com/linux/v6.8-rc1/source/include/linux/page_ref.h#L…
Kernel outputs an error line related to direct I/O:
https://syzkaller.appspot.com/text?tag=CrashLog&x=14ab52dac80000
The problem can be fixed in 5.10 and 5.15 stable releases by the
following patch.
The patch replaces page_mapped() call with check that finds additional
references to the page excluding page cache and filesystem private data.
If additional references exist, the page cannot be freed.
This version does not include the first patch from the first version.
The problem can be fixed without it.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Link: https://syzkaller.appspot.com/bug?extid=02f21431b65c214aa1d6
Matthew Wilcox (Oracle) (1):
mm/truncate: Replace page_mapped() call in invalidate_inode_page()
mm/truncate.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--
2.34.1
shutdown_pirq and startup_pirq are not taking the
irq_mapping_update_lock because they can't due to lock inversion. Both
are called with the irq_desc->lock being taking. The lock order,
however, is first irq_mapping_update_lock and then irq_desc->lock.
This opens multiple races:
- shutdown_pirq can be interrupted by a function that allocates an event
channel:
CPU0 CPU1
shutdown_pirq {
xen_evtchn_close(e)
__startup_pirq {
EVTCHNOP_bind_pirq
-> returns just freed evtchn e
set_evtchn_to_irq(e, irq)
}
xen_irq_info_cleanup() {
set_evtchn_to_irq(e, -1)
}
}
Assume here event channel e refers here to the same event channel
number.
After this race the evtchn_to_irq mapping for e is invalid (-1).
- __startup_pirq races with __unbind_from_irq in a similar way. Because
__startup_pirq doesn't take irq_mapping_update_lock it can grab the
evtchn that __unbind_from_irq is currently freeing and cleaning up. In
this case even though the event channel is allocated, its mapping can
be unset in evtchn_to_irq.
The fix is to first cleanup the mappings and then close the event
channel. In this way, when an event channel gets allocated it's
potential previous evtchn_to_irq mappings are guaranteed to be unset already.
This is also the reverse order of the allocation where first the event
channel is allocated and then the mappings are setup.
On a 5.10 kernel prior to commit 3fcdaf3d7634 ("xen/events: modify internal
[un]bind interfaces"), we hit a BUG like the following during probing of NVMe
devices. The issue is that during nvme_setup_io_queues, pci_free_irq
is called for every device which results in a call to shutdown_pirq.
With many nvme devices it's therefore likely to hit this race during
boot because there will be multiple calls to shutdown_pirq and
startup_pirq are running potentially in parallel.
------------[ cut here ]------------
blkfront: xvda: barrier or flush: disabled; persistent grants: enabled; indirect descriptors: enabled; bounce buffer: enabled
kernel BUG at drivers/xen/events/events_base.c:499!
invalid opcode: 0000 [#1] SMP PTI
CPU: 44 PID: 375 Comm: kworker/u257:23 Not tainted 5.10.201-191.748.amzn2.x86_64 #1
Hardware name: Xen HVM domU, BIOS 4.11.amazon 08/24/2006
Workqueue: nvme-reset-wq nvme_reset_work
RIP: 0010:bind_evtchn_to_cpu+0xdf/0xf0
Code: 5d 41 5e c3 cc cc cc cc 44 89 f7 e8 2b 55 ad ff 49 89 c5 48 85 c0 0f 84 64 ff ff ff 4c 8b 68 30 41 83 fe ff 0f 85 60 ff ff ff <0f> 0b 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 0f 1f 44 00 00
RSP: 0000:ffffc9000d533b08 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000006
RDX: 0000000000000028 RSI: 00000000ffffffff RDI: 00000000ffffffff
RBP: ffff888107419680 R08: 0000000000000000 R09: ffffffff82d72b00
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000000001ed
R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff88bc8b500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000002610001 CR4: 00000000001706e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
? show_trace_log_lvl+0x1c1/0x2d9
? show_trace_log_lvl+0x1c1/0x2d9
? set_affinity_irq+0xdc/0x1c0
? __die_body.cold+0x8/0xd
? die+0x2b/0x50
? do_trap+0x90/0x110
? bind_evtchn_to_cpu+0xdf/0xf0
? do_error_trap+0x65/0x80
? bind_evtchn_to_cpu+0xdf/0xf0
? exc_invalid_op+0x4e/0x70
? bind_evtchn_to_cpu+0xdf/0xf0
? asm_exc_invalid_op+0x12/0x20
? bind_evtchn_to_cpu+0xdf/0xf0
? bind_evtchn_to_cpu+0xc5/0xf0
set_affinity_irq+0xdc/0x1c0
irq_do_set_affinity+0x1d7/0x1f0
irq_setup_affinity+0xd6/0x1a0
irq_startup+0x8a/0xf0
__setup_irq+0x639/0x6d0
? nvme_suspend+0x150/0x150
request_threaded_irq+0x10c/0x180
? nvme_suspend+0x150/0x150
pci_request_irq+0xa8/0xf0
? __blk_mq_free_request+0x74/0xa0
queue_request_irq+0x6f/0x80
nvme_create_queue+0x1af/0x200
nvme_create_io_queues+0xbd/0xf0
nvme_setup_io_queues+0x246/0x320
? nvme_irq_check+0x30/0x30
nvme_reset_work+0x1c8/0x400
process_one_work+0x1b0/0x350
worker_thread+0x49/0x310
? process_one_work+0x350/0x350
kthread+0x11b/0x140
? __kthread_bind_mask+0x60/0x60
ret_from_fork+0x22/0x30
Modules linked in:
---[ end trace a11715de1eee1873 ]---
Fixes: d46a78b05c0e ("xen: implement pirq type event channels")
Cc: stable(a)vger.kernel.org
Co-debugged-by: Andrew Panyakin <apanyaki(a)amazon.com>
Signed-off-by: Maximilian Heyne <mheyne(a)amazon.de>
---
drivers/xen/events/events_base.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
index b8cfea7812d6..3b9f080109d7 100644
--- a/drivers/xen/events/events_base.c
+++ b/drivers/xen/events/events_base.c
@@ -923,8 +923,8 @@ static void shutdown_pirq(struct irq_data *data)
return;
do_mask(info, EVT_MASK_REASON_EXPLICIT);
- xen_evtchn_close(evtchn);
xen_irq_info_cleanup(info);
+ xen_evtchn_close(evtchn);
}
static void enable_pirq(struct irq_data *data)
@@ -956,6 +956,7 @@ EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
static void __unbind_from_irq(struct irq_info *info, unsigned int irq)
{
evtchn_port_t evtchn;
+ bool close_evtchn = false;
if (!info) {
xen_irq_free_desc(irq);
@@ -975,7 +976,7 @@ static void __unbind_from_irq(struct irq_info *info, unsigned int irq)
struct xenbus_device *dev;
if (!info->is_static)
- xen_evtchn_close(evtchn);
+ close_evtchn = true;
switch (info->type) {
case IRQT_VIRQ:
@@ -995,6 +996,9 @@ static void __unbind_from_irq(struct irq_info *info, unsigned int irq)
}
xen_irq_info_cleanup(info);
+
+ if (close_evtchn)
+ xen_evtchn_close(evtchn);
}
xen_free_irq(info);
--
2.40.1
Amazon Development Center Germany GmbH
Krausenstr. 38
10117 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 149173 B
Sitz: Berlin
Ust-ID: DE 289 237 879
This reverts commit 1e35f074399dece73d5df11847d4a0d7a6f49434.
Given that ERROR_RECOVERY calls into PORT_RESET for Hi-Zing
the CC pins, setting CC pins to default state during PORT_RESET
breaks error recovery.
4.5.2.2.2.1 ErrorRecovery State Requirements
The port shall not drive VBUS or VCONN, and shall present a
high-impedance to ground (above zOPEN) on its CC1 and CC2 pins.
Hi-Zing the CC pins is the inteded behavior for PORT_RESET.
CC pins are set to default state after tErrorRecovery in
PORT_RESET_WAIT_OFF.
4.5.2.2.2.2 Exiting From ErrorRecovery State
A Sink shall transition to Unattached.SNK after tErrorRecovery.
A Source shall transition to Unattached.SRC after tErrorRecovery.
Cc: stable(a)vger.kernel.org
Cc: Frank Wang <frank.wang(a)rock-chips.com>
Fixes: 1e35f074399d ("usb: typec: tcpm: fix cc role at port reset")
Signed-off-by: Badhri Jagan Sridharan <badhri(a)google.com>
---
drivers/usb/typec/tcpm/tcpm.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 5945e3a2b0f7..9d410718eaf4 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -4876,8 +4876,7 @@ static void run_state_machine(struct tcpm_port *port)
break;
case PORT_RESET:
tcpm_reset_port(port);
- tcpm_set_cc(port, tcpm_default_state(port) == SNK_UNATTACHED ?
- TYPEC_CC_RD : tcpm_rp_cc(port));
+ tcpm_set_cc(port, TYPEC_CC_OPEN);
tcpm_set_state(port, PORT_RESET_WAIT_OFF,
PD_T_ERROR_RECOVERY);
break;
base-commit: 933bb7b878ddd0f8c094db45551a7daddf806e00
--
2.43.0.429.g432eaa2c6b-goog
When we are in a syscall we will only save the FPSIMD subset even though
the task still has access to the full register set, and on context switch
we will only remove TIF_SVE when loading the register state. This means
that the signal handling code should not assume that TIF_SVE means that
the register state is stored in SVE format, it should instead check the
format that was recorded during save.
Fixes: 8c845e273104 ("arm64/sve: Leave SVE enabled on syscall if we don't context switch")
Signed-off-by: Mark Brown <broonie(a)kernel.org>
Cc: stable(a)vger.kernel.org
---
Changes in v2:
- Rebase onto v6.8-rc2.
- Link to v1: https://lore.kernel.org/r/20240119-arm64-sve-signal-regs-v1-1-b9fd61b0289a@…
---
arch/arm64/kernel/fpsimd.c | 2 +-
arch/arm64/kernel/signal.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index a5dc6f764195..25ceaee6b025 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -1635,7 +1635,7 @@ void fpsimd_preserve_current_state(void)
void fpsimd_signal_preserve_current_state(void)
{
fpsimd_preserve_current_state();
- if (test_thread_flag(TIF_SVE))
+ if (current->thread.fp_type == FP_STATE_SVE)
sve_to_fpsimd(current);
}
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 0e8beb3349ea..425b1bc17a3f 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -242,7 +242,7 @@ static int preserve_sve_context(struct sve_context __user *ctx)
vl = task_get_sme_vl(current);
vq = sve_vq_from_vl(vl);
flags |= SVE_SIG_FLAG_SM;
- } else if (test_thread_flag(TIF_SVE)) {
+ } else if (current->thread.fp_type == FP_STATE_SVE) {
vq = sve_vq_from_vl(vl);
}
@@ -878,7 +878,7 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user,
if (system_supports_sve() || system_supports_sme()) {
unsigned int vq = 0;
- if (add_all || test_thread_flag(TIF_SVE) ||
+ if (add_all || current->thread.fp_type == FP_STATE_SVE ||
thread_sm_enabled(¤t->thread)) {
int vl = max(sve_max_vl(), sme_max_vl());
---
base-commit: 41bccc98fb7931d63d03f326a746ac4d429c1dd3
change-id: 20240118-arm64-sve-signal-regs-5711e0d10425
Best regards,
--
Mark Brown <broonie(a)kernel.org>
In the RISC-V specification, the stimecmp register doesn't have a default
value. To prevent the timer interrupt from being triggered during timer
initialization, clear the timer interrupt by writing stimecmp with a
maximum value.
Fixes: 9f7a8ff6391f ("RISC-V: Prefer sstc extension if available")
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Ley Foon Tan <leyfoon.tan(a)starfivetech.com>
---
v2:
Resolved comments from Anup.
- Moved riscv_clock_event_stop() to riscv_timer_starting_cpu().
- Added Fixes tag
---
drivers/clocksource/timer-riscv.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/clocksource/timer-riscv.c b/drivers/clocksource/timer-riscv.c
index e66dcbd66566..672669eb7281 100644
--- a/drivers/clocksource/timer-riscv.c
+++ b/drivers/clocksource/timer-riscv.c
@@ -116,6 +116,9 @@ static int riscv_timer_starting_cpu(unsigned int cpu)
ce->rating = 450;
clockevents_config_and_register(ce, riscv_timebase, 100, 0x7fffffff);
+ /* Clear timer interrupt */
+ riscv_clock_event_stop();
+
enable_percpu_irq(riscv_clock_event_irq,
irq_get_trigger_type(riscv_clock_event_irq));
return 0;
--
2.43.0
On x86 each cpu_hw_events maintains a table for counter assignment but
it missed to update one for the deleted event in x86_pmu_del(). This
can make perf_clear_dirty_counters() reset used counter if it's called
before event scheduling or enabling. Then it would return out of range
data which doesn't make sense.
The following code can reproduce the problem.
$ cat repro.c
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <linux/perf_event.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/syscall.h>
struct perf_event_attr attr = {
.type = PERF_TYPE_HARDWARE,
.config = PERF_COUNT_HW_CPU_CYCLES,
.disabled = 1,
};
void *worker(void *arg)
{
int cpu = (long)arg;
int fd1 = syscall(SYS_perf_event_open, &attr, -1, cpu, -1, 0);
int fd2 = syscall(SYS_perf_event_open, &attr, -1, cpu, -1, 0);
void *p;
do {
ioctl(fd1, PERF_EVENT_IOC_ENABLE, 0);
p = mmap(NULL, 4096, PROT_READ, MAP_SHARED, fd1, 0);
ioctl(fd2, PERF_EVENT_IOC_ENABLE, 0);
ioctl(fd2, PERF_EVENT_IOC_DISABLE, 0);
munmap(p, 4096);
ioctl(fd1, PERF_EVENT_IOC_DISABLE, 0);
} while (1);
return NULL;
}
int main(void)
{
int i;
int n = sysconf(_SC_NPROCESSORS_ONLN);
pthread_t *th = calloc(n, sizeof(*th));
for (i = 0; i < n; i++)
pthread_create(&th[i], NULL, worker, (void *)(long)i);
for (i = 0; i < n; i++)
pthread_join(th[i], NULL);
free(th);
return 0;
}
And you can see the out of range data using perf stat like this.
Probably it'd be easier to see on a large machine.
$ gcc -o repro repro.c -pthread
$ ./repro &
$ sudo perf stat -A -I 1000 2>&1 | awk '{ if (length($3) > 15) print }'
1.001028462 CPU6 196,719,295,683,763 cycles # 194290.996 GHz (71.54%)
1.001028462 CPU3 396,077,485,787,730 branch-misses # 15804359784.80% of all branches (71.07%)
1.001028462 CPU17 197,608,350,727,877 branch-misses # 14594186554.56% of all branches (71.22%)
2.020064073 CPU4 198,372,472,612,140 cycles # 194681.113 GHz (70.95%)
2.020064073 CPU6 199,419,277,896,696 cycles # 195720.007 GHz (70.57%)
2.020064073 CPU20 198,147,174,025,639 cycles # 194474.654 GHz (71.03%)
2.020064073 CPU20 198,421,240,580,145 stalled-cycles-frontend # 100.14% frontend cycles idle (70.93%)
3.037443155 CPU4 197,382,689,923,416 cycles # 194043.065 GHz (71.30%)
3.037443155 CPU20 196,324,797,879,414 cycles # 193003.773 GHz (71.69%)
3.037443155 CPU5 197,679,956,608,205 stalled-cycles-backend # 1315606428.66% backend cycles idle (71.19%)
3.037443155 CPU5 198,571,860,474,851 instructions # 13215422.58 insn per cycle
It should move the contents in the cpuc->assign as well.
Fixes: 5471eea5d3bf ("perf/x86: Reset the dirty counter to prevent the leak for an RDPMC task")
Cc: Kan Liang <kan.liang(a)linux.intel.com>
Cc: stable(a)vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung(a)kernel.org>
---
arch/x86/events/core.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index 09050641ce5d..5b0dd07b1ef1 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1644,6 +1644,7 @@ static void x86_pmu_del(struct perf_event *event, int flags)
while (++i < cpuc->n_events) {
cpuc->event_list[i-1] = cpuc->event_list[i];
cpuc->event_constraint[i-1] = cpuc->event_constraint[i];
+ cpuc->assign[i-1] = cpuc->assign[i];
}
cpuc->event_constraint[i-1] = NULL;
--cpuc->n_events;
--
2.43.0.472.g3155946c3a-goog
The detection of dirty-throttled tasks in blk-wbt has been subtly broken
since its beginning in 2016. Namely if we are doing cgroup writeback and
the throttled task is not in the root cgroup, balance_dirty_pages() will
set dirty_sleep for the non-root bdi_writeback structure. However
blk-wbt checks dirty_sleep only in the root cgroup bdi_writeback
structure. Thus detection of recently throttled tasks is not working in
this case (we noticed this when we switched to cgroup v2 and suddently
writeback was slow).
Since blk-wbt has no easy way to get to proper bdi_writeback and
furthermore its intention has always been to work on the whole device
rather than on individual cgroups, just move the dirty_sleep timestamp
from bdi_writeback to backing_dev_info. That fixes the checking for
recently throttled task and saves memory for everybody as a bonus.
CC: stable(a)vger.kernel.org
Fixes: b57d74aff9ab ("writeback: track if we're sleeping on progress in balance_dirty_pages()")
Signed-off-by: Jan Kara <jack(a)suse.cz>
---
block/blk-wbt.c | 4 ++--
include/linux/backing-dev-defs.h | 7 +++++--
mm/backing-dev.c | 2 +-
mm/page-writeback.c | 2 +-
4 files changed, 9 insertions(+), 6 deletions(-)
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 5ba3cd574eac..0c0e270a8265 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -163,9 +163,9 @@ static void wb_timestamp(struct rq_wb *rwb, unsigned long *var)
*/
static bool wb_recent_wait(struct rq_wb *rwb)
{
- struct bdi_writeback *wb = &rwb->rqos.disk->bdi->wb;
+ struct backing_dev_info *bdi = rwb->rqos.disk->bdi;
- return time_before(jiffies, wb->dirty_sleep + HZ);
+ return time_before(jiffies, bdi->last_bdp_sleep + HZ);
}
static inline struct rq_wait *get_rq_wait(struct rq_wb *rwb,
diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h
index ae12696ec492..ad17739a2e72 100644
--- a/include/linux/backing-dev-defs.h
+++ b/include/linux/backing-dev-defs.h
@@ -141,8 +141,6 @@ struct bdi_writeback {
struct delayed_work dwork; /* work item used for writeback */
struct delayed_work bw_dwork; /* work item used for bandwidth estimate */
- unsigned long dirty_sleep; /* last wait */
-
struct list_head bdi_node; /* anchored at bdi->wb_list */
#ifdef CONFIG_CGROUP_WRITEBACK
@@ -179,6 +177,11 @@ struct backing_dev_info {
* any dirty wbs, which is depended upon by bdi_has_dirty().
*/
atomic_long_t tot_write_bandwidth;
+ /*
+ * Jiffies when last process was dirty throttled on this bdi. Used by
+ * blk-wbt.
+ */
+ unsigned long last_bdp_sleep;
struct bdi_writeback wb; /* the root writeback info for this bdi */
struct list_head wb_list; /* list of all wbs */
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 1e3447bccdb1..e039d05304dd 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -436,7 +436,6 @@ static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi,
INIT_LIST_HEAD(&wb->work_list);
INIT_DELAYED_WORK(&wb->dwork, wb_workfn);
INIT_DELAYED_WORK(&wb->bw_dwork, wb_update_bandwidth_workfn);
- wb->dirty_sleep = jiffies;
err = fprop_local_init_percpu(&wb->completions, gfp);
if (err)
@@ -921,6 +920,7 @@ int bdi_init(struct backing_dev_info *bdi)
INIT_LIST_HEAD(&bdi->bdi_list);
INIT_LIST_HEAD(&bdi->wb_list);
init_waitqueue_head(&bdi->wb_waitq);
+ bdi->last_bdp_sleep = jiffies;
return cgwb_bdi_init(bdi);
}
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index cd4e4ae77c40..cc37fa7f3364 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1921,7 +1921,7 @@ static int balance_dirty_pages(struct bdi_writeback *wb,
break;
}
__set_current_state(TASK_KILLABLE);
- wb->dirty_sleep = now;
+ bdi->last_bdp_sleep = jiffies;
io_schedule_timeout(pause);
current->dirty_paused_when = now + pause;
--
2.35.3