December 2024 - Linux-stable-mirror

[PATCH AUTOSEL 5.10 1/2] uprobes: sanitiize xol_free_insn_slot()

by Sasha Levin

From: Oleg Nesterov <oleg(a)redhat.com> [ Upstream commit c7b4133c48445dde789ed30b19ccb0448c7593f7 ] 1. Clear utask->xol_vaddr unconditionally, even if this addr is not valid, xol_free_insn_slot() should never return with utask->xol_vaddr != NULL. 2. Add a comment to explain why do we need to validate slot_addr. 3. Simplify the validation above. We can simply check offset < PAGE_SIZE, unsigned underflows are fine, it should work if slot_addr < area->vaddr. 4. Kill the unnecessary "slot_nr >= UINSNS_PER_PAGE" check, slot_nr must be valid if offset < PAGE_SIZE. The next patches will cleanup this function even more. Signed-off-by: Oleg Nesterov <oleg(a)redhat.com> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Link: https://lore.kernel.org/r/20240929144235.GA9471@redhat.com Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- kernel/events/uprobes.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 1ea2c1f311261..220d5f4a57e6b 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1634,8 +1634,8 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe) static void xol_free_insn_slot(struct task_struct *tsk) { struct xol_area *area; - unsigned long vma_end; unsigned long slot_addr; + unsigned long offset; if (!tsk->mm || !tsk->mm->uprobes_state.xol_area || !tsk->utask) return; @@ -1644,24 +1644,21 @@ static void xol_free_insn_slot(struct task_struct *tsk) if (unlikely(!slot_addr)) return; + tsk->utask->xol_vaddr = 0; area = tsk->mm->uprobes_state.xol_area; - vma_end = area->vaddr + PAGE_SIZE; - if (area->vaddr <= slot_addr && slot_addr < vma_end) { - unsigned long offset; - int slot_nr; - - offset = slot_addr - area->vaddr; - slot_nr = offset / UPROBE_XOL_SLOT_BYTES; - if (slot_nr >= UINSNS_PER_PAGE) - return; + offset = slot_addr - area->vaddr; + /* + * slot_addr must fit into [area->vaddr, area->vaddr + PAGE_SIZE). + * This check can only fail if the "[uprobes]" vma was mremap'ed. + */ + if (offset < PAGE_SIZE) { + int slot_nr = offset / UPROBE_XOL_SLOT_BYTES; clear_bit(slot_nr, area->bitmap); atomic_dec(&area->slot_count); smp_mb__after_atomic(); /* pairs with prepare_to_wait() */ if (waitqueue_active(&area->wq)) wake_up(&area->wq); - - tsk->utask->xol_vaddr = 0; } } -- 2.43.0

4 months, 2 weeks

2
2
0 0

[PATCH AUTOSEL 5.10 1/5] s390/cpum_sf: Handle CPU hotplug remove during sampling

by Sasha Levin

From: Thomas Richter <tmricht(a)linux.ibm.com> [ Upstream commit a0bd7dacbd51c632b8e2c0500b479af564afadf3 ] CPU hotplug remove handling triggers the following function call sequence: CPUHP_AP_PERF_S390_SF_ONLINE --> s390_pmu_sf_offline_cpu() ... CPUHP_AP_PERF_ONLINE --> perf_event_exit_cpu() The s390 CPUMF sampling CPU hotplug handler invokes: s390_pmu_sf_offline_cpu() +--> cpusf_pmu_setup() +--> setup_pmc_cpu() +--> deallocate_buffers() This function de-allocates all sampling data buffers (SDBs) allocated for that CPU at event initialization. It also clears the PMU_F_RESERVED bit. The CPU is gone and can not be sampled. With the event still being active on the removed CPU, the CPU event hotplug support in kernel performance subsystem triggers the following function calls on the removed CPU: perf_event_exit_cpu() +--> perf_event_exit_cpu_context() +--> __perf_event_exit_context() +--> __perf_remove_from_context() +--> event_sched_out() +--> cpumsf_pmu_del() +--> cpumsf_pmu_stop() +--> hw_perf_event_update() to stop and remove the event. During removal of the event, the sampling device driver tries to read out the remaining samples from the sample data buffers (SDBs). But they have already been freed (and may have been re-assigned). This may lead to a use after free situation in which case the samples are most likely invalid. In the best case the memory has not been reassigned and still contains valid data. Remedy this situation and check if the CPU is still in reserved state (bit PMU_F_RESERVED set). In this case the SDBs have not been released an contain valid data. This is always the case when the event is removed (and no CPU hotplug off occured). If the PMU_F_RESERVED bit is not set, the SDB buffers are gone. Signed-off-by: Thomas Richter <tmricht(a)linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner(a)linux.ibm.com> Signed-off-by: Heiko Carstens <hca(a)linux.ibm.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- arch/s390/kernel/perf_cpum_sf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c index a9e05f4d0a483..fc45f123f3bdc 100644 --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -1896,7 +1896,9 @@ static void cpumsf_pmu_stop(struct perf_event *event, int flags) event->hw.state |= PERF_HES_STOPPED; if ((flags & PERF_EF_UPDATE) && !(event->hw.state & PERF_HES_UPTODATE)) { - hw_perf_event_update(event, 1); + /* CPU hotplug off removes SDBs. No samples to extract. */ + if (cpuhw->flags & PMU_F_RESERVED) + hw_perf_event_update(event, 1); event->hw.state |= PERF_HES_UPTODATE; } perf_pmu_enable(event->pmu); -- 2.43.0

4 months, 2 weeks

2
5
0 0

[PATCH AUTOSEL 4.19 1/2] s390/cpum_sf: Handle CPU hotplug remove during sampling

by Sasha Levin

From: Thomas Richter <tmricht(a)linux.ibm.com> [ Upstream commit a0bd7dacbd51c632b8e2c0500b479af564afadf3 ] CPU hotplug remove handling triggers the following function call sequence: CPUHP_AP_PERF_S390_SF_ONLINE --> s390_pmu_sf_offline_cpu() ... CPUHP_AP_PERF_ONLINE --> perf_event_exit_cpu() The s390 CPUMF sampling CPU hotplug handler invokes: s390_pmu_sf_offline_cpu() +--> cpusf_pmu_setup() +--> setup_pmc_cpu() +--> deallocate_buffers() This function de-allocates all sampling data buffers (SDBs) allocated for that CPU at event initialization. It also clears the PMU_F_RESERVED bit. The CPU is gone and can not be sampled. With the event still being active on the removed CPU, the CPU event hotplug support in kernel performance subsystem triggers the following function calls on the removed CPU: perf_event_exit_cpu() +--> perf_event_exit_cpu_context() +--> __perf_event_exit_context() +--> __perf_remove_from_context() +--> event_sched_out() +--> cpumsf_pmu_del() +--> cpumsf_pmu_stop() +--> hw_perf_event_update() to stop and remove the event. During removal of the event, the sampling device driver tries to read out the remaining samples from the sample data buffers (SDBs). But they have already been freed (and may have been re-assigned). This may lead to a use after free situation in which case the samples are most likely invalid. In the best case the memory has not been reassigned and still contains valid data. Remedy this situation and check if the CPU is still in reserved state (bit PMU_F_RESERVED set). In this case the SDBs have not been released an contain valid data. This is always the case when the event is removed (and no CPU hotplug off occured). If the PMU_F_RESERVED bit is not set, the SDB buffers are gone. Signed-off-by: Thomas Richter <tmricht(a)linux.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner(a)linux.ibm.com> Signed-off-by: Heiko Carstens <hca(a)linux.ibm.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- arch/s390/kernel/perf_cpum_sf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/s390/kernel/perf_cpum_sf.c b/arch/s390/kernel/perf_cpum_sf.c index c7f94b5d93968..e51babd0bbc10 100644 --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -1772,7 +1772,9 @@ static void cpumsf_pmu_stop(struct perf_event *event, int flags) event->hw.state |= PERF_HES_STOPPED; if ((flags & PERF_EF_UPDATE) && !(event->hw.state & PERF_HES_UPTODATE)) { - hw_perf_event_update(event, 1); + /* CPU hotplug off removes SDBs. No samples to extract. */ + if (cpuhw->flags & PMU_F_RESERVED) + hw_perf_event_update(event, 1); event->hw.state |= PERF_HES_UPTODATE; } perf_pmu_enable(event->pmu); -- 2.43.0

4 months, 2 weeks

2
2
0 0

[PATCH AUTOSEL 6.1 1/6] ASoC: audio-graph-card2: Purge absent supplies for device tree nodes

by Sasha Levin

From: John Watts <contact(a)jookia.org> [ Upstream commit f8da001ae7af0abd9f6250c02c01a1121074ca60 ] The audio graph card doesn't mark its subnodes such as multi {}, dpcm {} and c2c {} as not requiring any suppliers. This causes a hang as Linux waits for these phantom suppliers to show up on boot. Make it clear these nodes have no suppliers. Example error message: [ 15.208558] platform 2034000.i2s: deferred probe pending: platform: wait for supplier /sound/multi [ 15.208584] platform sound: deferred probe pending: asoc-audio-graph-card2: parse error Signed-off-by: John Watts <contact(a)jookia.org> Acked-by: Kuninori Morimoto <kuninori.morimoto.gx(a)renesas.com> Link: https://patch.msgid.link/20241108-graph_dt_fix-v1-1-173e2f9603d6@jookia.org Signed-off-by: Mark Brown <broonie(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- sound/soc/generic/audio-graph-card2.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/sound/soc/generic/audio-graph-card2.c b/sound/soc/generic/audio-graph-card2.c index 8ac6df645ee6c..33f35eaa76a8b 100644 --- a/sound/soc/generic/audio-graph-card2.c +++ b/sound/soc/generic/audio-graph-card2.c @@ -249,16 +249,19 @@ static enum graph_type __graph_get_type(struct device_node *lnk) if (of_node_name_eq(np, GRAPH_NODENAME_MULTI)) { ret = GRAPH_MULTI; + fw_devlink_purge_absent_suppliers(&np->fwnode); goto out_put; } if (of_node_name_eq(np, GRAPH_NODENAME_DPCM)) { ret = GRAPH_DPCM; + fw_devlink_purge_absent_suppliers(&np->fwnode); goto out_put; } if (of_node_name_eq(np, GRAPH_NODENAME_C2C)) { ret = GRAPH_C2C; + fw_devlink_purge_absent_suppliers(&np->fwnode); goto out_put; } -- 2.43.0

4 months, 2 weeks

2
6
0 0

[PATCH AUTOSEL 5.10 1/6] soc: qcom: Add check devm_kasprintf() returned value

by Sasha Levin

From: Charles Han <hanchunchao(a)inspur.com> [ Upstream commit e694d2b5c58ba2d1e995d068707c8d966e7f5f2a ] devm_kasprintf() can return a NULL pointer on failure but this returned value in qcom_socinfo_probe() is not checked. Signed-off-by: Charles Han <hanchunchao(a)inspur.com> Link: https://lore.kernel.org/r/20240929072349.202520-1-hanchunchao@inspur.com Signed-off-by: Bjorn Andersson <andersson(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- drivers/soc/qcom/socinfo.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/soc/qcom/socinfo.c b/drivers/soc/qcom/socinfo.c index 60c82dcaa8d1d..7bb3543e42e59 100644 --- a/drivers/soc/qcom/socinfo.c +++ b/drivers/soc/qcom/socinfo.c @@ -507,10 +507,16 @@ static int qcom_socinfo_probe(struct platform_device *pdev) qs->attr.revision = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%u.%u", SOCINFO_MAJOR(le32_to_cpu(info->ver)), SOCINFO_MINOR(le32_to_cpu(info->ver))); - if (offsetof(struct socinfo, serial_num) <= item_size) + if (!qs->attr.soc_id || qs->attr.revision) + return -ENOMEM; + + if (offsetof(struct socinfo, serial_num) <= item_size) { qs->attr.serial_number = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%u", le32_to_cpu(info->serial_num)); + if (!qs->attr.serial_number) + return -ENOMEM; + } qs->soc_dev = soc_device_register(&qs->attr); if (IS_ERR(qs->soc_dev)) -- 2.43.0

4 months, 2 weeks

3
7
0 0

[PATCH] sched/deadline: Fix replenish_dl_new_period dl_server condition

by Juri Lelli

The condition in replenish_dl_new_period() that checks if a reservation (dl_server) is deferred and is not handling a starvation case is obviously wrong. Fix it. Cc: stable(a)vger.kernel.org Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Vincent Guittot <vincent.guittot(a)linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann(a)arm.com> Cc: Steven Rostedt <rostedt(a)goodmis.org> Cc: Ben Segall <bsegall(a)google.com> Cc: Mel Gorman <mgorman(a)suse.de> Cc: Valentin Schneider <vschneid(a)redhat.com> Fixes: a110a81c52a9 ("sched/deadline: Deferrable dl server") Signed-off-by: Juri Lelli <juri.lelli(a)redhat.com> --- kernel/sched/deadline.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index d9d5a702f1a6..206691d35b7d 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -781,7 +781,7 @@ static inline void replenish_dl_new_period(struct sched_dl_entity *dl_se, * If it is a deferred reservation, and the server * is not handling an starvation case, defer it. */ - if (dl_se->dl_defer & !dl_se->dl_defer_running) { + if (dl_se->dl_defer && !dl_se->dl_defer_running) { dl_se->dl_throttled = 1; dl_se->dl_defer_armed = 1; } -- 2.47.0

4 months, 2 weeks

2
1
0 0

[PATCH V2 1/4] perf/x86/intel/ds: Unconditionally drain PEBS DS when changing PEBS_DATA_CFG

by kan.liang＠linux.intel.com

From: Kan Liang <kan.liang(a)linux.intel.com> The PEBS kernel warnings can still be observed with the below case. when the below commands are running in parallel for a while. while true; do perf record --no-buildid -a --intr-regs=AX \ -e cpu/event=0xd0,umask=0x81/pp \ -c 10003 -o /dev/null ./triad; done & while true; do perf record -e 'cpu/mem-loads,ldlat=3/uP' -W -d -- ./dtlb done The commit b752ea0c28e3 ("perf/x86/intel/ds: Flush PEBS DS when changing PEBS_DATA_CFG") intends to flush the entire PEBS buffer before the hardware is reprogrammed. However, it fails in the above case. The first perf command utilizes the large PEBS, while the second perf command only utilizes a single PEBS. When the second perf event is added, only the n_pebs++. The intel_pmu_pebs_enable() is invoked after intel_pmu_pebs_add(). So the cpuc->n_pebs == cpuc->n_large_pebs check in the intel_pmu_drain_large_pebs() fails. The PEBS DS is not flushed. The new PEBS event should not be taken into account when flushing the existing PEBS DS. The check is unnecessary here. Before the hardware is reprogrammed, all the stale records must be drained unconditionally. For single PEBS or PEBS-vi-pt, the DS must be empty. The drain_pebs() can handle the empty case. There is no harm to unconditionally drain the PEBS DS. Fixes: b752ea0c28e3 ("perf/x86/intel/ds: Flush PEBS DS when changing PEBS_DATA_CFG") Signed-off-by: Kan Liang <kan.liang(a)linux.intel.com> Cc: stable(a)vger.kernel.org --- arch/x86/events/intel/ds.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c index 8afc4ad3cd16..1a4b326ca2ce 100644 --- a/arch/x86/events/intel/ds.c +++ b/arch/x86/events/intel/ds.c @@ -1489,7 +1489,7 @@ void intel_pmu_pebs_enable(struct perf_event *event) * hence we need to drain when changing said * size. */ - intel_pmu_drain_large_pebs(cpuc); + intel_pmu_drain_pebs_buffer(); adaptive_pebs_record_size_update(); wrmsrl(MSR_PEBS_DATA_CFG, pebs_data_cfg); cpuc->active_pebs_data_cfg = pebs_data_cfg; -- 2.38.1

4 months, 2 weeks

2
1
0 0

[PATCH v2] mtd: ubi: Added a check for ubi_num

by Denis Arefev

Added a check for ubi_num for negative numbers If the variable ubi_num takes negative values then we get: qemu-system-arm ... -append "ubi.mtd=0,0,0,-22222345" ... [ 0.745065] ubi_attach_mtd_dev from ubi_init+0x178/0x218 [ 0.745230] ubi_init from do_one_initcall+0x70/0x1ac [ 0.745344] do_one_initcall from kernel_init_freeable+0x198/0x224 [ 0.745474] kernel_init_freeable from kernel_init+0x18/0x134 [ 0.745600] kernel_init from ret_from_fork+0x14/0x28 [ 0.745727] Exception stack(0x90015fb0 to 0x90015ff8) Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 83ff59a06663 ("UBI: support ubi_num on mtd.ubi command line") Cc: stable(a)vger.kernel.org Signed-off-by: Denis Arefev <arefev(a)swemel.ru> --- V1 -> V2: changed the tag Fixes and moved the check to ubi_mtd_param_parse() drivers/mtd/ubi/build.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index 30be4ed68fad..ef6a22f372f9 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -1537,7 +1537,7 @@ static int ubi_mtd_param_parse(const char *val, const struct kernel_param *kp) if (token) { int err = kstrtoint(token, 10, &p->ubi_num); - if (err) { + if (err || p->ubi_num < UBI_DEV_NUM_AUTO) { pr_err("UBI error: bad value for ubi_num parameter: %s\n", token); return -EINVAL; -- 2.25.1

4 months, 2 weeks

2
1
0 0

FAILED: patch "[PATCH] xen: Fix the issue of resource not being properly released in" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y git checkout FETCH_HEAD git cherry-pick -x afc545da381ba0c651b2658966ac737032676f01 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024120221-serving-certainly-75b1@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From afc545da381ba0c651b2658966ac737032676f01 Mon Sep 17 00:00:00 2001 From: Qiu-ji Chen <chenqiuji666(a)gmail.com> Date: Tue, 5 Nov 2024 21:09:19 +0800 Subject: [PATCH] xen: Fix the issue of resource not being properly released in xenbus_dev_probe() This patch fixes an issue in the function xenbus_dev_probe(). In the xenbus_dev_probe() function, within the if (err) branch at line 313, the program incorrectly returns err directly without releasing the resources allocated by err = drv->probe(dev, id). As the return value is non-zero, the upper layers assume the processing logic has failed. However, the probe operation was performed earlier without a corresponding remove operation. Since the probe actually allocates resources, failing to perform the remove operation could lead to problems. To fix this issue, we followed the resource release logic of the xenbus_dev_remove() function by adding a new block fail_remove before the fail_put block. After entering the branch if (err) at line 313, the function will use a goto statement to jump to the fail_remove block, ensuring that the previously acquired resources are correctly released, thus preventing the reference count leak. This bug was identified by an experimental static analysis tool developed by our team. The tool specializes in analyzing reference count operations and detecting potential issues where resources are not properly managed. In this case, the tool flagged the missing release operation as a potential problem, which led to the development of this patch. Fixes: 4bac07c993d0 ("xen: add the Xenbus sysfs and virtual device hotplug driver") Cc: stable(a)vger.kernel.org Signed-off-by: Qiu-ji Chen <chenqiuji666(a)gmail.com> Reviewed-by: Juergen Gross <jgross(a)suse.com> Message-ID: <20241105130919.4621-1-chenqiuji666(a)gmail.com> Signed-off-by: Juergen Gross <jgross(a)suse.com> diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index 9f097f1f4a4c..6d32ffb01136 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -313,7 +313,7 @@ int xenbus_dev_probe(struct device *_dev) if (err) { dev_warn(&dev->dev, "watch_otherend on %s failed.\n", dev->nodename); - return err; + goto fail_remove; } dev->spurious_threshold = 1; @@ -322,6 +322,12 @@ int xenbus_dev_probe(struct device *_dev) dev->nodename); return 0; +fail_remove: + if (drv->remove) { + down(&dev->reclaim_sem); + drv->remove(dev); + up(&dev->reclaim_sem); + } fail_put: module_put(drv->driver.owner); fail:

4 months, 2 weeks

1
0
0 0

FAILED: patch "[PATCH] xen: Fix the issue of resource not being properly released in" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

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>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x afc545da381ba0c651b2658966ac737032676f01 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024120220-amuck-esophagus-6542@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From afc545da381ba0c651b2658966ac737032676f01 Mon Sep 17 00:00:00 2001 From: Qiu-ji Chen <chenqiuji666(a)gmail.com> Date: Tue, 5 Nov 2024 21:09:19 +0800 Subject: [PATCH] xen: Fix the issue of resource not being properly released in xenbus_dev_probe() This patch fixes an issue in the function xenbus_dev_probe(). In the xenbus_dev_probe() function, within the if (err) branch at line 313, the program incorrectly returns err directly without releasing the resources allocated by err = drv->probe(dev, id). As the return value is non-zero, the upper layers assume the processing logic has failed. However, the probe operation was performed earlier without a corresponding remove operation. Since the probe actually allocates resources, failing to perform the remove operation could lead to problems. To fix this issue, we followed the resource release logic of the xenbus_dev_remove() function by adding a new block fail_remove before the fail_put block. After entering the branch if (err) at line 313, the function will use a goto statement to jump to the fail_remove block, ensuring that the previously acquired resources are correctly released, thus preventing the reference count leak. This bug was identified by an experimental static analysis tool developed by our team. The tool specializes in analyzing reference count operations and detecting potential issues where resources are not properly managed. In this case, the tool flagged the missing release operation as a potential problem, which led to the development of this patch. Fixes: 4bac07c993d0 ("xen: add the Xenbus sysfs and virtual device hotplug driver") Cc: stable(a)vger.kernel.org Signed-off-by: Qiu-ji Chen <chenqiuji666(a)gmail.com> Reviewed-by: Juergen Gross <jgross(a)suse.com> Message-ID: <20241105130919.4621-1-chenqiuji666(a)gmail.com> Signed-off-by: Juergen Gross <jgross(a)suse.com> diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index 9f097f1f4a4c..6d32ffb01136 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -313,7 +313,7 @@ int xenbus_dev_probe(struct device *_dev) if (err) { dev_warn(&dev->dev, "watch_otherend on %s failed.\n", dev->nodename); - return err; + goto fail_remove; } dev->spurious_threshold = 1; @@ -322,6 +322,12 @@ int xenbus_dev_probe(struct device *_dev) dev->nodename); return 0; +fail_remove: + if (drv->remove) { + down(&dev->reclaim_sem); + drv->remove(dev); + up(&dev->reclaim_sem); + } fail_put: module_put(drv->driver.owner); fail:

4 months, 2 weeks

1
0
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror December 2024