Re: [PATCH v3 1/1] kasan: fix object remain in offline per-cpu quarantine
On Thu, 2020-12-03 at 12:28 -0800, Andrew Morton wrote:
> On Thu, 3 Dec 2020 13:46:59 +0100 Andrey Konovalov
> wrote:
>
> > > #define QLIST_INIT { NULL, NULL, 0 }
> > > @@ -188,6 +190,11 @@ void quarantine_put(struct kasan_free_meta *info,
> > > struct kmem_cache *cache)
> > > local_irq_save(flags);
> > >
> > > q = this_cpu_ptr(&cpu_quarantine);
> > > + if (q->offline) {
> > > + qlink_free(&info->quarantine_link, cache);
> >
> > Hi Kuan-Ying,
> >
> > This needs to be rebased onto the mm tree: it has some KASAN patches
> > that touch this code and rename the info variable to meta.
>
> Yup. I'm taking care of that.
Hi Andrew,
Sorry about that.
I will fix that conflict.
Thanks.
Re: [PATCH v3 1/1] kasan: fix object remain in offline per-cpu quarantine
On Thu, 3 Dec 2020 13:46:59 +0100 Andrey Konovalov
wrote:
> > #define QLIST_INIT { NULL, NULL, 0 }
> > @@ -188,6 +190,11 @@ void quarantine_put(struct kasan_free_meta *info,
> > struct kmem_cache *cache)
> > local_irq_save(flags);
> >
> > q = this_cpu_ptr(&cpu_quarantine);
> > + if (q->offline) {
> > + qlink_free(&info->quarantine_link, cache);
>
> Hi Kuan-Ying,
>
> This needs to be rebased onto the mm tree: it has some KASAN patches
> that touch this code and rename the info variable to meta.
Yup. I'm taking care of that.
Re: [PATCH v3 1/1] kasan: fix object remain in offline per-cpu quarantine
On Wed, 2020-12-02 at 15:53 +0800, Kuan-Ying Lee wrote: > We hit this issue in our internal test. > When enabling generic kasan, a kfree()'d object is put into per-cpu > quarantine first. If the cpu goes offline, object still remains in > the per-cpu quarantine. If we call kmem_cache_destroy() now, slub > will report "Objects remaining" error. Reverting this commit on the top of today's linux-next fixed memory corruptions while doing CPU hotplug. .config: https://cailca.coding.net/public/linux/mm/git/files/master/x86.config [ 421.539476][ T120] BUG kmalloc-128 (Not tainted): Object already free [ 421.546047][ T120] - [ 421.546047][ T120] [ 421.557165][ T120] INFO: Allocated in memcg_alloc_page_obj_cgroups+0x86/0x140 age=755 cpu=21 pid=2316 [ 421.566533][ T120] __slab_alloc+0x55/0x70 [ 421.570744][ T120] __kmalloc_node+0xdc/0x280 [ 421.575215][ T120] memcg_alloc_page_obj_cgroups+0x86/0x140 [ 421.580910][ T120] allocate_slab+0xd8/0x610 [ 421.585299][ T120] ___slab_alloc+0x4cb/0x830 [ 421.589770][ T120] __slab_alloc+0x55/0x70 [ 421.593985][ T120] kmem_cache_alloc+0x225/0x280 [ 421.598724][ T120] vm_area_dup+0x76/0x2a0 [ 421.602940][ T120] __split_vma+0x90/0x4b0 [ 421.607151][ T120] mprotect_fixup+0x5da/0x7d0 [ 421.611712][ T120] do_mprotect_pkey+0x41a/0x7c0 [ 421.616447][ T120] __x64_sys_mprotect+0x74/0xb0 [ 421.621181][ T120] do_syscall_64+0x33/0x40 [ 421.625479][ T120] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 421.631262][ T120] INFO: Freed in quarantine_put+0xb5/0x1b0 age=3 cpu=21 pid=120 [ 421.638795][ T120] quarantine_put+0xe7/0x1b0 [ 421.643270][ T120] slab_free_freelist_hook+0x71/0x1a0 [ 421.648529][ T120] kfree+0xe2/0x5d0 [ 421.652215][ T120] __free_slab+0x1f8/0x300 [ 421.656517][ T120] qlist_free_all+0x56/0xc0 [ 421.660903][ T120] kasan_cpu_offline+0x1a/0x20 [ 421.665550][ T120] cpuhp_invoke_callback+0x1dd/0x1530 [ 421.670811][ T120] cpuhp_thread_fun+0x343/0x690 [ 421.675547][ T120] smpboot_thread_fn+0x30f/0x780 [ 421.680371][ T120] kthread+0x359/0x420 [ 421.684317][ T120] ret_from_fork+0x22/0x30 [ 421.688616][ T120] INFO: Slab 0x80d42669 objects=12 used=11 fp=0x0ce8ce1d flags=0x4bfffc10201 [ 421.699031][ T120] INFO: Object 0x0ce8ce1d @offset=1408 fp=0x [ 421.699031][ T120] [ 421.709186][ T120] Redzone 2d1421b0: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb [ 421.719339][ T120] Redzone 18565a7c: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb [ 421.729492][ T120] Redzone d8a699c9: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb [ 421.739645][ T120] Redzone af065f39: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb [ 421.749800][ T120] Redzone 480c8db9: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb [ 421.759954][ T120] Redzone c37ee06b: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb [ 421.770106][ T120] Redzone 40f9cbf1: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb [ 421.780256][ T120] Redzone e714e01e: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb [ 421.790408][ T120] Object 0ce8ce1d: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b [ 421.800471][ T120] Object 46eb4462: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b [ 421.810536][ T120] Object c3a122ae: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b [ 421.820599][ T120] Object d0195822: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b [ 421.830665][ T120] Object 8332e5f7: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b [ 421.840729][ T120] Object a04f77eb: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b [ 421.850796][ T120] Object 326e9ce3: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b [ 421.860862][ T120] Object fa32b4b7: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5 kkk. [ 421.870926][ T120] Redzone 1d59aa8f: bb bb bb bb bb bb bb bb [ 421.880382][ T120] Padding f49e6727: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a [ 421.890537][ T120] Padding 7eb7befd: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a [ 421.900691][ T120] Padding c69f7c35: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a [ 421.910842][ T120] CPU: 21 PID: 120 Comm: cpuhp/21 Tainted: GB 5.10.0-rc6-next-20201203+ #8 [ 421.920733][ T120] Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019 [ 421.930011][ T120] Call Trace:
Re: [PATCH v3 1/1] kasan: fix object remain in offline per-cpu quarantine
On Wed, Dec 2, 2020 at 8:58 AM Kuan-Ying Lee wrote:
>
> We hit this issue in our internal test.
> When enabling generic kasan, a kfree()'d object is put into per-cpu
> quarantine first. If the cpu goes offline, object still remains in
> the per-cpu quarantine. If we call kmem_cache_destroy() now, slub
> will report "Objects remaining" error.
>
> [ 74.982625]
> =
> [ 74.983380] BUG test_module_slab (Not tainted): Objects remaining in
> test_module_slab on __kmem_cache_shutdown()
> [ 74.984145]
> -
> [ 74.984145]
> [ 74.984883] Disabling lock debugging due to kernel taint
> [ 74.985561] INFO: Slab 0x(ptrval) objects=34 used=1
> fp=0x(ptrval) flags=0x20010200
> [ 74.986638] CPU: 3 PID: 176 Comm: cat Tainted: GB
> 5.10.0-rc1-7-g4525c8781ec0-dirty #10
> [ 74.987262] Hardware name: linux,dummy-virt (DT)
> [ 74.987606] Call trace:
> [ 74.987924] dump_backtrace+0x0/0x2b0
> [ 74.988296] show_stack+0x18/0x68
> [ 74.988698] dump_stack+0xfc/0x168
> [ 74.989030] slab_err+0xac/0xd4
> [ 74.989346] __kmem_cache_shutdown+0x1e4/0x3c8
> [ 74.989779] kmem_cache_destroy+0x68/0x130
> [ 74.990176] test_version_show+0x84/0xf0
> [ 74.990679] module_attr_show+0x40/0x60
> [ 74.991218] sysfs_kf_seq_show+0x128/0x1c0
> [ 74.991656] kernfs_seq_show+0xa0/0xb8
> [ 74.992059] seq_read+0x1f0/0x7e8
> [ 74.992415] kernfs_fop_read+0x70/0x338
> [ 74.993051] vfs_read+0xe4/0x250
> [ 74.993498] ksys_read+0xc8/0x180
> [ 74.993825] __arm64_sys_read+0x44/0x58
> [ 74.994203] el0_svc_common.constprop.0+0xac/0x228
> [ 74.994708] do_el0_svc+0x38/0xa0
> [ 74.995088] el0_sync_handler+0x170/0x178
> [ 74.995497] el0_sync+0x174/0x180
> [ 74.996050] INFO: Object 0x(ptrval) @offset=15848
> [ 74.996752] INFO: Allocated in test_version_show+0x98/0xf0 age=8188 cpu=6
> pid=172
> [ 75.000802] stack_trace_save+0x9c/0xd0
> [ 75.002420] set_track+0x64/0xf0
> [ 75.002770] alloc_debug_processing+0x104/0x1a0
> [ 75.003171] ___slab_alloc+0x628/0x648
> [ 75.004213] __slab_alloc.isra.0+0x2c/0x58
> [ 75.004757] kmem_cache_alloc+0x560/0x588
> [ 75.005376] test_version_show+0x98/0xf0
> [ 75.005756] module_attr_show+0x40/0x60
> [ 75.007035] sysfs_kf_seq_show+0x128/0x1c0
> [ 75.007433] kernfs_seq_show+0xa0/0xb8
> [ 75.007800] seq_read+0x1f0/0x7e8
> [ 75.008128] kernfs_fop_read+0x70/0x338
> [ 75.008507] vfs_read+0xe4/0x250
> [ 75.008990] ksys_read+0xc8/0x180
> [ 75.009462] __arm64_sys_read+0x44/0x58
> [ 75.010085] el0_svc_common.constprop.0+0xac/0x228
> [ 75.011006] kmem_cache_destroy test_module_slab: Slab cache still has
> objects
>
> Register a cpu hotplug function to remove all objects in the offline
> per-cpu quarantine when cpu is going offline. Set a per-cpu variable
> to indicate this cpu is offline.
>
> Signed-off-by: Kuan-Ying Lee
> Suggested-by: Dmitry Vyukov
> Reported-by: Guangye Yang
> Cc: Andrey Ryabinin
> Cc: Alexander Potapenko
> Cc: Andrew Morton
> Cc: Matthias Brugger
> ---
> mm/kasan/quarantine.c | 40
> 1 file changed, 40 insertions(+)
>
> diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c
> index 4c5375810449..cac7c617df72 100644
> --- a/mm/kasan/quarantine.c
> +++ b/mm/kasan/quarantine.c
> @@ -29,6 +29,7 @@
> #include
> #include
> #include
> +#include
>
> #include "../slab.h"
> #include "kasan.h"
> @@ -43,6 +44,7 @@ struct qlist_head {
> struct qlist_node *head;
> struct qlist_node *tail;
> size_t bytes;
> + bool offline;
> };
>
> #define QLIST_INIT { NULL, NULL, 0 }
> @@ -188,6 +190,11 @@ void quarantine_put(struct kasan_free_meta *info, struct
> kmem_cache *cache)
> local_irq_save(flags);
>
> q = this_cpu_ptr(&cpu_quarantine);
> + if (q->offline) {
> + qlink_free(&info->quarantine_link, cache);
Hi Kuan-Ying,
This needs to be rebased onto the mm tree: it has some KASAN patches
that touch this code and rename the info variable to meta.
Thanks!
> + local_irq_restore(flags);
> + return;
> + }
> qlist_put(q, &info->quarantine_link, cache->size);
> if (unlikely(q->bytes > QUARANTINE_PERCPU_SIZE)) {
> qlist_move_all(q, &temp);
> @@ -328,3 +335,36 @@ void quarantine_remove_cache(struct kmem_cache *cache)
>
> synchronize_srcu(&remove_cache_srcu);
> }
> +
> +static int kasan_cpu_online(unsigned int cpu)
> +{
> + this_cpu_ptr(&cpu_quarantine)->offline = false;
> + return 0;
> +}
> +
> +static int kasan_cpu_offline(unsigned int cpu)
> +{
> + struct qlist_head *q;
> +
> + q = this_cpu_ptr(&cpu_quarantine);
> + /* Ensure the ordering between the writing to q->offline and
> +* qlist_free_a
Re: [PATCH v3 1/1] kasan: fix object remain in offline per-cpu quarantine
On Wed, Dec 2, 2020 at 8:58 AM Kuan-Ying Lee wrote:
>
> We hit this issue in our internal test.
> When enabling generic kasan, a kfree()'d object is put into per-cpu
> quarantine first. If the cpu goes offline, object still remains in
> the per-cpu quarantine. If we call kmem_cache_destroy() now, slub
> will report "Objects remaining" error.
>
> [ 74.982625]
> =
> [ 74.983380] BUG test_module_slab (Not tainted): Objects remaining in
> test_module_slab on __kmem_cache_shutdown()
> [ 74.984145]
> -
> [ 74.984145]
> [ 74.984883] Disabling lock debugging due to kernel taint
> [ 74.985561] INFO: Slab 0x(ptrval) objects=34 used=1
> fp=0x(ptrval) flags=0x20010200
> [ 74.986638] CPU: 3 PID: 176 Comm: cat Tainted: GB
> 5.10.0-rc1-7-g4525c8781ec0-dirty #10
> [ 74.987262] Hardware name: linux,dummy-virt (DT)
> [ 74.987606] Call trace:
> [ 74.987924] dump_backtrace+0x0/0x2b0
> [ 74.988296] show_stack+0x18/0x68
> [ 74.988698] dump_stack+0xfc/0x168
> [ 74.989030] slab_err+0xac/0xd4
> [ 74.989346] __kmem_cache_shutdown+0x1e4/0x3c8
> [ 74.989779] kmem_cache_destroy+0x68/0x130
> [ 74.990176] test_version_show+0x84/0xf0
> [ 74.990679] module_attr_show+0x40/0x60
> [ 74.991218] sysfs_kf_seq_show+0x128/0x1c0
> [ 74.991656] kernfs_seq_show+0xa0/0xb8
> [ 74.992059] seq_read+0x1f0/0x7e8
> [ 74.992415] kernfs_fop_read+0x70/0x338
> [ 74.993051] vfs_read+0xe4/0x250
> [ 74.993498] ksys_read+0xc8/0x180
> [ 74.993825] __arm64_sys_read+0x44/0x58
> [ 74.994203] el0_svc_common.constprop.0+0xac/0x228
> [ 74.994708] do_el0_svc+0x38/0xa0
> [ 74.995088] el0_sync_handler+0x170/0x178
> [ 74.995497] el0_sync+0x174/0x180
> [ 74.996050] INFO: Object 0x(ptrval) @offset=15848
> [ 74.996752] INFO: Allocated in test_version_show+0x98/0xf0 age=8188 cpu=6
> pid=172
> [ 75.000802] stack_trace_save+0x9c/0xd0
> [ 75.002420] set_track+0x64/0xf0
> [ 75.002770] alloc_debug_processing+0x104/0x1a0
> [ 75.003171] ___slab_alloc+0x628/0x648
> [ 75.004213] __slab_alloc.isra.0+0x2c/0x58
> [ 75.004757] kmem_cache_alloc+0x560/0x588
> [ 75.005376] test_version_show+0x98/0xf0
> [ 75.005756] module_attr_show+0x40/0x60
> [ 75.007035] sysfs_kf_seq_show+0x128/0x1c0
> [ 75.007433] kernfs_seq_show+0xa0/0xb8
> [ 75.007800] seq_read+0x1f0/0x7e8
> [ 75.008128] kernfs_fop_read+0x70/0x338
> [ 75.008507] vfs_read+0xe4/0x250
> [ 75.008990] ksys_read+0xc8/0x180
> [ 75.009462] __arm64_sys_read+0x44/0x58
> [ 75.010085] el0_svc_common.constprop.0+0xac/0x228
> [ 75.011006] kmem_cache_destroy test_module_slab: Slab cache still has
> objects
>
> Register a cpu hotplug function to remove all objects in the offline
> per-cpu quarantine when cpu is going offline. Set a per-cpu variable
> to indicate this cpu is offline.
>
> Signed-off-by: Kuan-Ying Lee
> Suggested-by: Dmitry Vyukov
> Reported-by: Guangye Yang
> Cc: Andrey Ryabinin
> Cc: Alexander Potapenko
> Cc: Andrew Morton
> Cc: Matthias Brugger
Looks good to me, thanks.
Reviewed-by: Dmitry Vyukov
> ---
> mm/kasan/quarantine.c | 40
> 1 file changed, 40 insertions(+)
>
> diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c
> index 4c5375810449..cac7c617df72 100644
> --- a/mm/kasan/quarantine.c
> +++ b/mm/kasan/quarantine.c
> @@ -29,6 +29,7 @@
> #include
> #include
> #include
> +#include
>
> #include "../slab.h"
> #include "kasan.h"
> @@ -43,6 +44,7 @@ struct qlist_head {
> struct qlist_node *head;
> struct qlist_node *tail;
> size_t bytes;
> + bool offline;
> };
>
> #define QLIST_INIT { NULL, NULL, 0 }
> @@ -188,6 +190,11 @@ void quarantine_put(struct kasan_free_meta *info, struct
> kmem_cache *cache)
> local_irq_save(flags);
>
> q = this_cpu_ptr(&cpu_quarantine);
> + if (q->offline) {
> + qlink_free(&info->quarantine_link, cache);
> + local_irq_restore(flags);
> + return;
> + }
> qlist_put(q, &info->quarantine_link, cache->size);
> if (unlikely(q->bytes > QUARANTINE_PERCPU_SIZE)) {
> qlist_move_all(q, &temp);
> @@ -328,3 +335,36 @@ void quarantine_remove_cache(struct kmem_cache *cache)
>
> synchronize_srcu(&remove_cache_srcu);
> }
> +
> +static int kasan_cpu_online(unsigned int cpu)
> +{
> + this_cpu_ptr(&cpu_quarantine)->offline = false;
> + return 0;
> +}
> +
> +static int kasan_cpu_offline(unsigned int cpu)
> +{
> + struct qlist_head *q;
> +
> + q = this_cpu_ptr(&cpu_quarantine);
> + /* Ensure the ordering between the writing to q->offline and
> +* qlist_free_all. Otherwise, cpu_quarantine may be corrupted
> +* by interrupt.
> +*/
> +
[PATCH v3 1/1] kasan: fix object remain in offline per-cpu quarantine
We hit this issue in our internal test.
When enabling generic kasan, a kfree()'d object is put into per-cpu
quarantine first. If the cpu goes offline, object still remains in
the per-cpu quarantine. If we call kmem_cache_destroy() now, slub
will report "Objects remaining" error.
[ 74.982625]
=
[ 74.983380] BUG test_module_slab (Not tainted): Objects remaining in
test_module_slab on __kmem_cache_shutdown()
[ 74.984145]
-
[ 74.984145]
[ 74.984883] Disabling lock debugging due to kernel taint
[ 74.985561] INFO: Slab 0x(ptrval) objects=34 used=1
fp=0x(ptrval) flags=0x20010200
[ 74.986638] CPU: 3 PID: 176 Comm: cat Tainted: GB
5.10.0-rc1-7-g4525c8781ec0-dirty #10
[ 74.987262] Hardware name: linux,dummy-virt (DT)
[ 74.987606] Call trace:
[ 74.987924] dump_backtrace+0x0/0x2b0
[ 74.988296] show_stack+0x18/0x68
[ 74.988698] dump_stack+0xfc/0x168
[ 74.989030] slab_err+0xac/0xd4
[ 74.989346] __kmem_cache_shutdown+0x1e4/0x3c8
[ 74.989779] kmem_cache_destroy+0x68/0x130
[ 74.990176] test_version_show+0x84/0xf0
[ 74.990679] module_attr_show+0x40/0x60
[ 74.991218] sysfs_kf_seq_show+0x128/0x1c0
[ 74.991656] kernfs_seq_show+0xa0/0xb8
[ 74.992059] seq_read+0x1f0/0x7e8
[ 74.992415] kernfs_fop_read+0x70/0x338
[ 74.993051] vfs_read+0xe4/0x250
[ 74.993498] ksys_read+0xc8/0x180
[ 74.993825] __arm64_sys_read+0x44/0x58
[ 74.994203] el0_svc_common.constprop.0+0xac/0x228
[ 74.994708] do_el0_svc+0x38/0xa0
[ 74.995088] el0_sync_handler+0x170/0x178
[ 74.995497] el0_sync+0x174/0x180
[ 74.996050] INFO: Object 0x(ptrval) @offset=15848
[ 74.996752] INFO: Allocated in test_version_show+0x98/0xf0 age=8188 cpu=6
pid=172
[ 75.000802] stack_trace_save+0x9c/0xd0
[ 75.002420] set_track+0x64/0xf0
[ 75.002770] alloc_debug_processing+0x104/0x1a0
[ 75.003171] ___slab_alloc+0x628/0x648
[ 75.004213] __slab_alloc.isra.0+0x2c/0x58
[ 75.004757] kmem_cache_alloc+0x560/0x588
[ 75.005376] test_version_show+0x98/0xf0
[ 75.005756] module_attr_show+0x40/0x60
[ 75.007035] sysfs_kf_seq_show+0x128/0x1c0
[ 75.007433] kernfs_seq_show+0xa0/0xb8
[ 75.007800] seq_read+0x1f0/0x7e8
[ 75.008128] kernfs_fop_read+0x70/0x338
[ 75.008507] vfs_read+0xe4/0x250
[ 75.008990] ksys_read+0xc8/0x180
[ 75.009462] __arm64_sys_read+0x44/0x58
[ 75.010085] el0_svc_common.constprop.0+0xac/0x228
[ 75.011006] kmem_cache_destroy test_module_slab: Slab cache still has objects
Register a cpu hotplug function to remove all objects in the offline
per-cpu quarantine when cpu is going offline. Set a per-cpu variable
to indicate this cpu is offline.
Signed-off-by: Kuan-Ying Lee
Suggested-by: Dmitry Vyukov
Reported-by: Guangye Yang
Cc: Andrey Ryabinin
Cc: Alexander Potapenko
Cc: Andrew Morton
Cc: Matthias Brugger
---
mm/kasan/quarantine.c | 40
1 file changed, 40 insertions(+)
diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c
index 4c5375810449..cac7c617df72 100644
--- a/mm/kasan/quarantine.c
+++ b/mm/kasan/quarantine.c
@@ -29,6 +29,7 @@
#include
#include
#include
+#include
#include "../slab.h"
#include "kasan.h"
@@ -43,6 +44,7 @@ struct qlist_head {
struct qlist_node *head;
struct qlist_node *tail;
size_t bytes;
+ bool offline;
};
#define QLIST_INIT { NULL, NULL, 0 }
@@ -188,6 +190,11 @@ void quarantine_put(struct kasan_free_meta *info, struct
kmem_cache *cache)
local_irq_save(flags);
q = this_cpu_ptr(&cpu_quarantine);
+ if (q->offline) {
+ qlink_free(&info->quarantine_link, cache);
+ local_irq_restore(flags);
+ return;
+ }
qlist_put(q, &info->quarantine_link, cache->size);
if (unlikely(q->bytes > QUARANTINE_PERCPU_SIZE)) {
qlist_move_all(q, &temp);
@@ -328,3 +335,36 @@ void quarantine_remove_cache(struct kmem_cache *cache)
synchronize_srcu(&remove_cache_srcu);
}
+
+static int kasan_cpu_online(unsigned int cpu)
+{
+ this_cpu_ptr(&cpu_quarantine)->offline = false;
+ return 0;
+}
+
+static int kasan_cpu_offline(unsigned int cpu)
+{
+ struct qlist_head *q;
+
+ q = this_cpu_ptr(&cpu_quarantine);
+ /* Ensure the ordering between the writing to q->offline and
+* qlist_free_all. Otherwise, cpu_quarantine may be corrupted
+* by interrupt.
+*/
+ WRITE_ONCE(q->offline, true);
+ barrier();
+ qlist_free_all(q, NULL);
+ return 0;
+}
+
+static int __init kasan_cpu_quarantine_init(void)
+{
+ int ret = 0;
+
+ ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "mm/kasan:online",
+ kasan_cpu_online, kasan_cpu_offline);
+ if (ret < 0)
+
