* [PATCH AUTOSEL 4.14 015/123] mm/cma.c: cma_declare_contiguous: correct err handling
[not found] <20190327181628.15899-1-sashal@kernel.org>
@ 2019-03-27 18:14 ` Sasha Levin
2019-03-27 18:14 ` [PATCH AUTOSEL 4.14 016/123] mm/page_ext.c: fix an imbalance with kmemleak Sasha Levin
` (4 subsequent siblings)
5 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2019-03-27 18:14 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Peng Fan, Laura Abbott, Joonsoo Kim, Michal Hocko,
Vlastimil Babka, Marek Szyprowski, Andrey Konovalov,
Andrew Morton, Linus Torvalds, Sasha Levin, linux-mm
From: Peng Fan <peng.fan@nxp.com>
[ Upstream commit 0d3bd18a5efd66097ef58622b898d3139790aa9d ]
In case cma_init_reserved_mem failed, need to free the memblock
allocated by memblock_reserve or memblock_alloc_range.
Quote Catalin's comments:
https://lkml.org/lkml/2019/2/26/482
Kmemleak is supposed to work with the memblock_{alloc,free} pair and it
ignores the memblock_reserve() as a memblock_alloc() implementation
detail. It is, however, tolerant to memblock_free() being called on
a sub-range or just a different range from a previous memblock_alloc().
So the original patch looks fine to me. FWIW:
Link: http://lkml.kernel.org/r/20190227144631.16708-1-peng.fan@nxp.com
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
mm/cma.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/mm/cma.c b/mm/cma.c
index 022e52bd8370..5749c9b3b5d0 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -348,12 +348,14 @@ int __init cma_declare_contiguous(phys_addr_t base,
ret = cma_init_reserved_mem(base, size, order_per_bit, name, res_cma);
if (ret)
- goto err;
+ goto free_mem;
pr_info("Reserved %ld MiB at %pa\n", (unsigned long)size / SZ_1M,
&base);
return 0;
+free_mem:
+ memblock_free(base, size);
err:
pr_err("Failed to reserve %ld MiB\n", (unsigned long)size / SZ_1M);
return ret;
--
2.19.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH AUTOSEL 4.14 016/123] mm/page_ext.c: fix an imbalance with kmemleak
[not found] <20190327181628.15899-1-sashal@kernel.org>
2019-03-27 18:14 ` [PATCH AUTOSEL 4.14 015/123] mm/cma.c: cma_declare_contiguous: correct err handling Sasha Levin
@ 2019-03-27 18:14 ` Sasha Levin
2019-03-27 18:14 ` [PATCH AUTOSEL 4.14 017/123] mm, mempolicy: fix uninit memory access Sasha Levin
` (3 subsequent siblings)
5 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2019-03-27 18:14 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Qian Cai, Andrew Morton, Linus Torvalds, Sasha Levin, linux-mm
From: Qian Cai <cai@lca.pw>
[ Upstream commit 0c81585499601acd1d0e1cbf424cabfaee60628c ]
After offlining a memory block, kmemleak scan will trigger a crash, as
it encounters a page ext address that has already been freed during
memory offlining. At the beginning in alloc_page_ext(), it calls
kmemleak_alloc(), but it does not call kmemleak_free() in
free_page_ext().
BUG: unable to handle kernel paging request at ffff888453d00000
PGD 128a01067 P4D 128a01067 PUD 128a04067 PMD 47e09e067 PTE 800ffffbac2ff060
Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
CPU: 1 PID: 1594 Comm: bash Not tainted 5.0.0-rc8+ #15
Hardware name: HP ProLiant DL180 Gen9/ProLiant DL180 Gen9, BIOS U20 10/25/2017
RIP: 0010:scan_block+0xb5/0x290
Code: 85 6e 01 00 00 48 b8 00 00 30 f5 81 88 ff ff 48 39 c3 0f 84 5b 01 00 00 48 89 d8 48 c1 e8 03 42 80 3c 20 00 0f 85 87 01 00 00 <4c> 8b 3b e8 f3 0c fa ff 4c 39 3d 0c 6b 4c 01 0f 87 08 01 00 00 4c
RSP: 0018:ffff8881ec57f8e0 EFLAGS: 00010082
RAX: 0000000000000000 RBX: ffff888453d00000 RCX: ffffffffa61e5a54
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888453d00000
RBP: ffff8881ec57f920 R08: fffffbfff4ed588d R09: fffffbfff4ed588c
R10: fffffbfff4ed588c R11: ffffffffa76ac463 R12: dffffc0000000000
R13: ffff888453d00ff9 R14: ffff8881f80cef48 R15: ffff8881f80cef48
FS: 00007f6c0e3f8740(0000) GS:ffff8881f7680000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff888453d00000 CR3: 00000001c4244003 CR4: 00000000001606a0
Call Trace:
scan_gray_list+0x269/0x430
kmemleak_scan+0x5a8/0x10f0
kmemleak_write+0x541/0x6ca
full_proxy_write+0xf8/0x190
__vfs_write+0xeb/0x980
vfs_write+0x15a/0x4f0
ksys_write+0xd2/0x1b0
__x64_sys_write+0x73/0xb0
do_syscall_64+0xeb/0xaaa
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f6c0dad73b8
Code: 89 02 48 c7 c0 ff ff ff ff eb b3 0f 1f 80 00 00 00 00 f3 0f 1e fa 48 8d 05 65 63 2d 00 8b 00 85 c0 75 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 41 54 49 89 d4 55
RSP: 002b:00007ffd5b863cb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f6c0dad73b8
RDX: 0000000000000005 RSI: 000055a9216e1710 RDI: 0000000000000001
RBP: 000055a9216e1710 R08: 000000000000000a R09: 00007ffd5b863840
R10: 000000000000000a R11: 0000000000000246 R12: 00007f6c0dda9780
R13: 0000000000000005 R14: 00007f6c0dda4740 R15: 0000000000000005
Modules linked in: nls_iso8859_1 nls_cp437 vfat fat kvm_intel kvm irqbypass efivars ip_tables x_tables xfs sd_mod ahci libahci igb i2c_algo_bit libata i2c_core dm_mirror dm_region_hash dm_log dm_mod efivarfs
CR2: ffff888453d00000
---[ end trace ccf646c7456717c5 ]---
Kernel panic - not syncing: Fatal exception
Shutting down cpus with NMI
Kernel Offset: 0x24c00000 from 0xffffffff81000000 (relocation range:
0xffffffff80000000-0xffffffffbfffffff)
---[ end Kernel panic - not syncing: Fatal exception ]---
Link: http://lkml.kernel.org/r/20190227173147.75650-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
mm/page_ext.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/mm/page_ext.c b/mm/page_ext.c
index 2c44f5b78435..dece2bdf86fe 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -271,6 +271,7 @@ static void free_page_ext(void *addr)
table_size = get_entry_size() * PAGES_PER_SECTION;
BUG_ON(PageReserved(page));
+ kmemleak_free(addr);
free_pages_exact(addr, table_size);
}
}
--
2.19.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH AUTOSEL 4.14 017/123] mm, mempolicy: fix uninit memory access
[not found] <20190327181628.15899-1-sashal@kernel.org>
2019-03-27 18:14 ` [PATCH AUTOSEL 4.14 015/123] mm/cma.c: cma_declare_contiguous: correct err handling Sasha Levin
2019-03-27 18:14 ` [PATCH AUTOSEL 4.14 016/123] mm/page_ext.c: fix an imbalance with kmemleak Sasha Levin
@ 2019-03-27 18:14 ` Sasha Levin
2019-03-27 18:14 ` [PATCH AUTOSEL 4.14 018/123] mm/vmalloc.c: fix kernel BUG at mm/vmalloc.c:512! Sasha Levin
` (2 subsequent siblings)
5 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2019-03-27 18:14 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Vlastimil Babka, Alexander Potapenko, Dmitry Vyukov,
Andrea Arcangeli, Kirill A. Shutemov, Michal Hocko,
David Rientjes, Yisheng Xie, zhong jiang, Andrew Morton,
Linus Torvalds, Sasha Levin, linux-mm
From: Vlastimil Babka <vbabka@suse.cz>
[ Upstream commit 2e25644e8da4ed3a27e7b8315aaae74660be72dc ]
Syzbot with KMSAN reports (excerpt):
==================================================================
BUG: KMSAN: uninit-value in mpol_rebind_policy mm/mempolicy.c:353 [inline]
BUG: KMSAN: uninit-value in mpol_rebind_mm+0x249/0x370 mm/mempolicy.c:384
CPU: 1 PID: 17420 Comm: syz-executor4 Not tainted 4.20.0-rc7+ #15
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x173/0x1d0 lib/dump_stack.c:113
kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:613
__msan_warning+0x82/0xf0 mm/kmsan/kmsan_instr.c:295
mpol_rebind_policy mm/mempolicy.c:353 [inline]
mpol_rebind_mm+0x249/0x370 mm/mempolicy.c:384
update_tasks_nodemask+0x608/0xca0 kernel/cgroup/cpuset.c:1120
update_nodemasks_hier kernel/cgroup/cpuset.c:1185 [inline]
update_nodemask kernel/cgroup/cpuset.c:1253 [inline]
cpuset_write_resmask+0x2a98/0x34b0 kernel/cgroup/cpuset.c:1728
...
Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:204 [inline]
kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:158
kmsan_kmalloc+0xa6/0x130 mm/kmsan/kmsan_hooks.c:176
kmem_cache_alloc+0x572/0xb90 mm/slub.c:2777
mpol_new mm/mempolicy.c:276 [inline]
do_mbind mm/mempolicy.c:1180 [inline]
kernel_mbind+0x8a7/0x31a0 mm/mempolicy.c:1347
__do_sys_mbind mm/mempolicy.c:1354 [inline]
As it's difficult to report where exactly the uninit value resides in
the mempolicy object, we have to guess a bit. mm/mempolicy.c:353
contains this part of mpol_rebind_policy():
if (!mpol_store_user_nodemask(pol) &&
nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
"mpol_store_user_nodemask(pol)" is testing pol->flags, which I couldn't
ever see being uninitialized after leaving mpol_new(). So I'll guess
it's actually about accessing pol->w.cpuset_mems_allowed on line 354,
but still part of statement starting on line 353.
For w.cpuset_mems_allowed to be not initialized, and the nodes_equal()
reachable for a mempolicy where mpol_set_nodemask() is called in
do_mbind(), it seems the only possibility is a MPOL_PREFERRED policy
with empty set of nodes, i.e. MPOL_LOCAL equivalent, with MPOL_F_LOCAL
flag. Let's exclude such policies from the nodes_equal() check. Note
the uninit access should be benign anyway, as rebinding this kind of
policy is always a no-op. Therefore no actual need for stable
inclusion.
Link: http://lkml.kernel.org/r/a71997c3-e8ae-a787-d5ce-3db05768b27c@suse.cz
Link: http://lkml.kernel.org/r/73da3e9c-cc84-509e-17d9-0c434bb9967d@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: syzbot+b19c2dc2c990ea657a71@syzkaller.appspotmail.com
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Yisheng Xie <xieyisheng1@huawei.com>
Cc: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
mm/mempolicy.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 1331645a3794..b0e99ea0c3db 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -349,7 +349,7 @@ static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask)
{
if (!pol)
return;
- if (!mpol_store_user_nodemask(pol) &&
+ if (!mpol_store_user_nodemask(pol) && !(pol->flags & MPOL_F_LOCAL) &&
nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
return;
--
2.19.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH AUTOSEL 4.14 018/123] mm/vmalloc.c: fix kernel BUG at mm/vmalloc.c:512!
[not found] <20190327181628.15899-1-sashal@kernel.org>
` (2 preceding siblings ...)
2019-03-27 18:14 ` [PATCH AUTOSEL 4.14 017/123] mm, mempolicy: fix uninit memory access Sasha Levin
@ 2019-03-27 18:14 ` Sasha Levin
2019-03-27 18:14 ` [PATCH AUTOSEL 4.14 019/123] mm/slab.c: kmemleak no scan alien caches Sasha Levin
2019-03-27 18:14 ` [PATCH AUTOSEL 4.14 024/123] page_poison: play nicely with KASAN Sasha Levin
5 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2019-03-27 18:14 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Uladzislau Rezki (Sony),
Ingo Molnar, Joel Fernandes, Matthew Wilcox, Michal Hocko,
Oleksiy Avramchenko, Steven Rostedt, Tejun Heo, Thomas Garnier,
Thomas Gleixner, Andrew Morton, Linus Torvalds, Sasha Levin,
linux-mm
From: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
[ Upstream commit afd07389d3f4933c7f7817a92fb5e053d59a3182 ]
One of the vmalloc stress test case triggers the kernel BUG():
<snip>
[60.562151] ------------[ cut here ]------------
[60.562154] kernel BUG at mm/vmalloc.c:512!
[60.562206] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[60.562247] CPU: 0 PID: 430 Comm: vmalloc_test/0 Not tainted 4.20.0+ #161
[60.562293] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
[60.562351] RIP: 0010:alloc_vmap_area+0x36f/0x390
<snip>
it can happen due to big align request resulting in overflowing of
calculated address, i.e. it becomes 0 after ALIGN()'s fixup.
Fix it by checking if calculated address is within vstart/vend range.
Link: http://lkml.kernel.org/r/20190124115648.9433-2-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
mm/vmalloc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 8d9f636d0c98..6c906f6f16cc 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -498,7 +498,11 @@ static struct vmap_area *alloc_vmap_area(unsigned long size,
}
found:
- if (addr + size > vend)
+ /*
+ * Check also calculated address against the vstart,
+ * because it can be 0 because of big align request.
+ */
+ if (addr + size > vend || addr < vstart)
goto overflow;
va->va_start = addr;
--
2.19.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH AUTOSEL 4.14 019/123] mm/slab.c: kmemleak no scan alien caches
[not found] <20190327181628.15899-1-sashal@kernel.org>
` (3 preceding siblings ...)
2019-03-27 18:14 ` [PATCH AUTOSEL 4.14 018/123] mm/vmalloc.c: fix kernel BUG at mm/vmalloc.c:512! Sasha Levin
@ 2019-03-27 18:14 ` Sasha Levin
2019-03-27 18:14 ` [PATCH AUTOSEL 4.14 024/123] page_poison: play nicely with KASAN Sasha Levin
5 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2019-03-27 18:14 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Qian Cai, Christoph Lameter, Pekka Enberg, David Rientjes,
Joonsoo Kim, Catalin Marinas, Andrew Morton, Linus Torvalds,
Sasha Levin, linux-mm
From: Qian Cai <cai@lca.pw>
[ Upstream commit 92d1d07daad65c300c7d0b68bbef8867e9895d54 ]
Kmemleak throws endless warnings during boot due to in
__alloc_alien_cache(),
alc = kmalloc_node(memsize, gfp, node);
init_arraycache(&alc->ac, entries, batch);
kmemleak_no_scan(ac);
Kmemleak does not track the array cache (alc->ac) but the alien cache
(alc) instead, so let it track the latter by lifting kmemleak_no_scan()
out of init_arraycache().
There is another place that calls init_arraycache(), but
alloc_kmem_cache_cpus() uses the percpu allocation where will never be
considered as a leak.
kmemleak: Found object by alias at 0xffff8007b9aa7e38
CPU: 190 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc2+ #2
Call trace:
dump_backtrace+0x0/0x168
show_stack+0x24/0x30
dump_stack+0x88/0xb0
lookup_object+0x84/0xac
find_and_get_object+0x84/0xe4
kmemleak_no_scan+0x74/0xf4
setup_kmem_cache_node+0x2b4/0x35c
__do_tune_cpucache+0x250/0x2d4
do_tune_cpucache+0x4c/0xe4
enable_cpucache+0xc8/0x110
setup_cpu_cache+0x40/0x1b8
__kmem_cache_create+0x240/0x358
create_cache+0xc0/0x198
kmem_cache_create_usercopy+0x158/0x20c
kmem_cache_create+0x50/0x64
fsnotify_init+0x58/0x6c
do_one_initcall+0x194/0x388
kernel_init_freeable+0x668/0x688
kernel_init+0x18/0x124
ret_from_fork+0x10/0x18
kmemleak: Object 0xffff8007b9aa7e00 (size 256):
kmemleak: comm "swapper/0", pid 1, jiffies 4294697137
kmemleak: min_count = 1
kmemleak: count = 0
kmemleak: flags = 0x1
kmemleak: checksum = 0
kmemleak: backtrace:
kmemleak_alloc+0x84/0xb8
kmem_cache_alloc_node_trace+0x31c/0x3a0
__kmalloc_node+0x58/0x78
setup_kmem_cache_node+0x26c/0x35c
__do_tune_cpucache+0x250/0x2d4
do_tune_cpucache+0x4c/0xe4
enable_cpucache+0xc8/0x110
setup_cpu_cache+0x40/0x1b8
__kmem_cache_create+0x240/0x358
create_cache+0xc0/0x198
kmem_cache_create_usercopy+0x158/0x20c
kmem_cache_create+0x50/0x64
fsnotify_init+0x58/0x6c
do_one_initcall+0x194/0x388
kernel_init_freeable+0x668/0x688
kernel_init+0x18/0x124
kmemleak: Not scanning unknown object at 0xffff8007b9aa7e38
CPU: 190 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc2+ #2
Call trace:
dump_backtrace+0x0/0x168
show_stack+0x24/0x30
dump_stack+0x88/0xb0
kmemleak_no_scan+0x90/0xf4
setup_kmem_cache_node+0x2b4/0x35c
__do_tune_cpucache+0x250/0x2d4
do_tune_cpucache+0x4c/0xe4
enable_cpucache+0xc8/0x110
setup_cpu_cache+0x40/0x1b8
__kmem_cache_create+0x240/0x358
create_cache+0xc0/0x198
kmem_cache_create_usercopy+0x158/0x20c
kmem_cache_create+0x50/0x64
fsnotify_init+0x58/0x6c
do_one_initcall+0x194/0x388
kernel_init_freeable+0x668/0x688
kernel_init+0x18/0x124
ret_from_fork+0x10/0x18
Link: http://lkml.kernel.org/r/20190129184518.39808-1-cai@lca.pw
Fixes: 1fe00d50a9e8 ("slab: factor out initialization of array cache")
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
mm/slab.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/mm/slab.c b/mm/slab.c
index 09df506ae830..f4658468b23e 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -563,14 +563,6 @@ static void start_cpu_timer(int cpu)
static void init_arraycache(struct array_cache *ac, int limit, int batch)
{
- /*
- * The array_cache structures contain pointers to free object.
- * However, when such objects are allocated or transferred to another
- * cache the pointers are not cleared and they could be counted as
- * valid references during a kmemleak scan. Therefore, kmemleak must
- * not scan such objects.
- */
- kmemleak_no_scan(ac);
if (ac) {
ac->avail = 0;
ac->limit = limit;
@@ -586,6 +578,14 @@ static struct array_cache *alloc_arraycache(int node, int entries,
struct array_cache *ac = NULL;
ac = kmalloc_node(memsize, gfp, node);
+ /*
+ * The array_cache structures contain pointers to free object.
+ * However, when such objects are allocated or transferred to another
+ * cache the pointers are not cleared and they could be counted as
+ * valid references during a kmemleak scan. Therefore, kmemleak must
+ * not scan such objects.
+ */
+ kmemleak_no_scan(ac);
init_arraycache(ac, entries, batchcount);
return ac;
}
@@ -680,6 +680,7 @@ static struct alien_cache *__alloc_alien_cache(int node, int entries,
alc = kmalloc_node(memsize, gfp, node);
if (alc) {
+ kmemleak_no_scan(alc);
init_arraycache(&alc->ac, entries, batch);
spin_lock_init(&alc->lock);
}
--
2.19.1
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH AUTOSEL 4.14 024/123] page_poison: play nicely with KASAN
[not found] <20190327181628.15899-1-sashal@kernel.org>
` (4 preceding siblings ...)
2019-03-27 18:14 ` [PATCH AUTOSEL 4.14 019/123] mm/slab.c: kmemleak no scan alien caches Sasha Levin
@ 2019-03-27 18:14 ` Sasha Levin
5 siblings, 0 replies; 6+ messages in thread
From: Sasha Levin @ 2019-03-27 18:14 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Qian Cai, Andrew Morton, Linus Torvalds, Sasha Levin, linux-mm
From: Qian Cai <cai@lca.pw>
[ Upstream commit 4117992df66a26fa33908b4969e04801534baab1 ]
KASAN does not play well with the page poisoning (CONFIG_PAGE_POISONING).
It triggers false positives in the allocation path:
BUG: KASAN: use-after-free in memchr_inv+0x2ea/0x330
Read of size 8 at addr ffff88881f800000 by task swapper/0
CPU: 0 PID: 0 Comm: swapper Not tainted 5.0.0-rc1+ #54
Call Trace:
dump_stack+0xe0/0x19a
print_address_description.cold.2+0x9/0x28b
kasan_report.cold.3+0x7a/0xb5
__asan_report_load8_noabort+0x19/0x20
memchr_inv+0x2ea/0x330
kernel_poison_pages+0x103/0x3d5
get_page_from_freelist+0x15e7/0x4d90
because KASAN has not yet unpoisoned the shadow page for allocation
before it checks memchr_inv() but only found a stale poison pattern.
Also, false positives in free path,
BUG: KASAN: slab-out-of-bounds in kernel_poison_pages+0x29e/0x3d5
Write of size 4096 at addr ffff8888112cc000 by task swapper/0/1
CPU: 5 PID: 1 Comm: swapper/0 Not tainted 5.0.0-rc1+ #55
Call Trace:
dump_stack+0xe0/0x19a
print_address_description.cold.2+0x9/0x28b
kasan_report.cold.3+0x7a/0xb5
check_memory_region+0x22d/0x250
memset+0x28/0x40
kernel_poison_pages+0x29e/0x3d5
__free_pages_ok+0x75f/0x13e0
due to KASAN adds poisoned redzones around slab objects, but the page
poisoning needs to poison the whole page.
Link: http://lkml.kernel.org/r/20190114233405.67843-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
mm/page_alloc.c | 2 +-
mm/page_poison.c | 4 ++++
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 40075c1946b3..923deb33bf34 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1764,8 +1764,8 @@ inline void post_alloc_hook(struct page *page, unsigned int order,
arch_alloc_page(page, order);
kernel_map_pages(page, 1 << order, 1);
- kernel_poison_pages(page, 1 << order, 1);
kasan_alloc_pages(page, order);
+ kernel_poison_pages(page, 1 << order, 1);
set_page_owner(page, order, gfp_flags);
}
diff --git a/mm/page_poison.c b/mm/page_poison.c
index e83fd44867de..a7ba9e315a12 100644
--- a/mm/page_poison.c
+++ b/mm/page_poison.c
@@ -6,6 +6,7 @@
#include <linux/page_ext.h>
#include <linux/poison.h>
#include <linux/ratelimit.h>
+#include <linux/kasan.h>
static bool want_page_poisoning __read_mostly;
@@ -34,7 +35,10 @@ static void poison_page(struct page *page)
{
void *addr = kmap_atomic(page);
+ /* KASAN still think the page is in-use, so skip it. */
+ kasan_disable_current();
memset(addr, PAGE_POISON, PAGE_SIZE);
+ kasan_enable_current();
kunmap_atomic(addr);
}
--
2.19.1
^ permalink raw reply [flat|nested] 6+ messages in thread