From: Filipe Manana <fdmanana(a)suse.com>
commit f9baa501b4fd6962257853d46ddffbc21f27e344 upstream.
There are a few exceptional cases where cloning an inline extent needs to
copy the inline extent data into a page of the destination inode.
When this happens, we end up starting a transaction while having a dirty
page for the destination inode and while having the range locked in the
destination's inode iotree too. Because when reserving metadata space
for a transaction we may need to flush existing delalloc in case there is
not enough free space, we have a mechanism in place to prevent a deadlock,
which was introduced in commit 3d45f221ce627d ("btrfs: fix deadlock when
cloning inline extent and low on free metadata space").
However when using qgroups, a transaction also reserves metadata qgroup
space, which can also result in flushing delalloc in case there is not
enough available space at the moment. When this happens we deadlock, since
flushing delalloc requires locking the file range in the inode's iotree
and the range was already locked at the very beginning of the clone
operation, before attempting to start the transaction.
When this issue happens, stack traces like the following are reported:
[72747.556262] task:kworker/u81:9 state:D stack: 0 pid: 225 ppid: 2 flags:0x00004000
[72747.556268] Workqueue: writeback wb_workfn (flush-btrfs-1142)
[72747.556271] Call Trace:
[72747.556273] __schedule+0x296/0x760
[72747.556277] schedule+0x3c/0xa0
[72747.556279] io_schedule+0x12/0x40
[72747.556284] __lock_page+0x13c/0x280
[72747.556287] ? generic_file_readonly_mmap+0x70/0x70
[72747.556325] extent_write_cache_pages+0x22a/0x440 [btrfs]
[72747.556331] ? __set_page_dirty_nobuffers+0xe7/0x160
[72747.556358] ? set_extent_buffer_dirty+0x5e/0x80 [btrfs]
[72747.556362] ? update_group_capacity+0x25/0x210
[72747.556366] ? cpumask_next_and+0x1a/0x20
[72747.556391] extent_writepages+0x44/0xa0 [btrfs]
[72747.556394] do_writepages+0x41/0xd0
[72747.556398] __writeback_single_inode+0x39/0x2a0
[72747.556403] writeback_sb_inodes+0x1ea/0x440
[72747.556407] __writeback_inodes_wb+0x5f/0xc0
[72747.556410] wb_writeback+0x235/0x2b0
[72747.556414] ? get_nr_inodes+0x35/0x50
[72747.556417] wb_workfn+0x354/0x490
[72747.556420] ? newidle_balance+0x2c5/0x3e0
[72747.556424] process_one_work+0x1aa/0x340
[72747.556426] worker_thread+0x30/0x390
[72747.556429] ? create_worker+0x1a0/0x1a0
[72747.556432] kthread+0x116/0x130
[72747.556435] ? kthread_park+0x80/0x80
[72747.556438] ret_from_fork+0x1f/0x30
[72747.566958] Workqueue: btrfs-flush_delalloc btrfs_work_helper [btrfs]
[72747.566961] Call Trace:
[72747.566964] __schedule+0x296/0x760
[72747.566968] ? finish_wait+0x80/0x80
[72747.566970] schedule+0x3c/0xa0
[72747.566995] wait_extent_bit.constprop.68+0x13b/0x1c0 [btrfs]
[72747.566999] ? finish_wait+0x80/0x80
[72747.567024] lock_extent_bits+0x37/0x90 [btrfs]
[72747.567047] btrfs_invalidatepage+0x299/0x2c0 [btrfs]
[72747.567051] ? find_get_pages_range_tag+0x2cd/0x380
[72747.567076] __extent_writepage+0x203/0x320 [btrfs]
[72747.567102] extent_write_cache_pages+0x2bb/0x440 [btrfs]
[72747.567106] ? update_load_avg+0x7e/0x5f0
[72747.567109] ? enqueue_entity+0xf4/0x6f0
[72747.567134] extent_writepages+0x44/0xa0 [btrfs]
[72747.567137] ? enqueue_task_fair+0x93/0x6f0
[72747.567140] do_writepages+0x41/0xd0
[72747.567144] __filemap_fdatawrite_range+0xc7/0x100
[72747.567167] btrfs_run_delalloc_work+0x17/0x40 [btrfs]
[72747.567195] btrfs_work_helper+0xc2/0x300 [btrfs]
[72747.567200] process_one_work+0x1aa/0x340
[72747.567202] worker_thread+0x30/0x390
[72747.567205] ? create_worker+0x1a0/0x1a0
[72747.567208] kthread+0x116/0x130
[72747.567211] ? kthread_park+0x80/0x80
[72747.567214] ret_from_fork+0x1f/0x30
[72747.569686] task:fsstress state:D stack: 0 pid:841421 ppid:841417 flags:0x00000000
[72747.569689] Call Trace:
[72747.569691] __schedule+0x296/0x760
[72747.569694] schedule+0x3c/0xa0
[72747.569721] try_flush_qgroup+0x95/0x140 [btrfs]
[72747.569725] ? finish_wait+0x80/0x80
[72747.569753] btrfs_qgroup_reserve_data+0x34/0x50 [btrfs]
[72747.569781] btrfs_check_data_free_space+0x5f/0xa0 [btrfs]
[72747.569804] btrfs_buffered_write+0x1f7/0x7f0 [btrfs]
[72747.569810] ? path_lookupat.isra.48+0x97/0x140
[72747.569833] btrfs_file_write_iter+0x81/0x410 [btrfs]
[72747.569836] ? __kmalloc+0x16a/0x2c0
[72747.569839] do_iter_readv_writev+0x160/0x1c0
[72747.569843] do_iter_write+0x80/0x1b0
[72747.569847] vfs_writev+0x84/0x140
[72747.569869] ? btrfs_file_llseek+0x38/0x270 [btrfs]
[72747.569873] do_writev+0x65/0x100
[72747.569876] do_syscall_64+0x33/0x40
[72747.569879] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[72747.569899] task:fsstress state:D stack: 0 pid:841424 ppid:841417 flags:0x00004000
[72747.569903] Call Trace:
[72747.569906] __schedule+0x296/0x760
[72747.569909] schedule+0x3c/0xa0
[72747.569936] try_flush_qgroup+0x95/0x140 [btrfs]
[72747.569940] ? finish_wait+0x80/0x80
[72747.569967] __btrfs_qgroup_reserve_meta+0x36/0x50 [btrfs]
[72747.569989] start_transaction+0x279/0x580 [btrfs]
[72747.570014] clone_copy_inline_extent+0x332/0x490 [btrfs]
[72747.570041] btrfs_clone+0x5b7/0x7a0 [btrfs]
[72747.570068] ? lock_extent_bits+0x64/0x90 [btrfs]
[72747.570095] btrfs_clone_files+0xfc/0x150 [btrfs]
[72747.570122] btrfs_remap_file_range+0x3d8/0x4a0 [btrfs]
[72747.570126] do_clone_file_range+0xed/0x200
[72747.570131] vfs_clone_file_range+0x37/0x110
[72747.570134] ioctl_file_clone+0x7d/0xb0
[72747.570137] do_vfs_ioctl+0x138/0x630
[72747.570140] __x64_sys_ioctl+0x62/0xc0
[72747.570143] do_syscall_64+0x33/0x40
[72747.570146] entry_SYSCALL_64_after_hwframe+0x44/0xa9
So fix this by skipping the flush of delalloc for an inode that is
flagged with BTRFS_INODE_NO_DELALLOC_FLUSH, meaning it is currently under
such a special case of cloning an inline extent, when flushing delalloc
during qgroup metadata reservation.
The special cases for cloning inline extents were added in kernel 5.7 by
by commit 05a5a7621ce66c ("Btrfs: implement full reflink support for
inline extents"), while having qgroup metadata space reservation flushing
delalloc when low on space was added in kernel 5.9 by commit
c53e9653605dbf ("btrfs: qgroup: try to flush qgroup space when we get
-EDQUOT"). So use a "Fixes:" tag for the later commit to ease stable
kernel backports.
Reported-by: Wang Yugui <wangyugui(a)e16-tech.com>
Link: https://lore.kernel.org/linux-btrfs/20210421083137.31E3.409509F4@e16-tech.c…
Fixes: c53e9653605dbf ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT")
CC: stable(a)vger.kernel.org # 5.9+
Reviewed-by: Qu Wenruo <wqu(a)suse.com>
Signed-off-by: Filipe Manana <fdmanana(a)suse.com>
Reviewed-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
[Shivani: Modified to apply on 5.10.y, Passed false to
btrfs_start_delalloc_flush() in fs/btrfs/transaction.c file to
maintain the default behaviour]
Signed-off-by: Shivani Agarwal <shivani.agarwal(a)broadcom.com>
---
fs/btrfs/ctree.h | 2 +-
fs/btrfs/inode.c | 4 ++--
fs/btrfs/ioctl.c | 2 +-
fs/btrfs/qgroup.c | 2 +-
fs/btrfs/send.c | 4 ++--
fs/btrfs/transaction.c | 2 +-
6 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 7ad3091db571..d9d6a57acafe 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3013,7 +3013,7 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
struct inode *inode, u64 new_size,
u32 min_type);
-int btrfs_start_delalloc_snapshot(struct btrfs_root *root);
+int btrfs_start_delalloc_snapshot(struct btrfs_root *root, bool in_reclaim_context);
int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, u64 nr,
bool in_reclaim_context);
int btrfs_set_extent_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8d7ca8a21525..99aad39fad13 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -9566,7 +9566,7 @@ static int start_delalloc_inodes(struct btrfs_root *root,
return ret;
}
-int btrfs_start_delalloc_snapshot(struct btrfs_root *root)
+int btrfs_start_delalloc_snapshot(struct btrfs_root *root, bool in_reclaim_context)
{
struct writeback_control wbc = {
.nr_to_write = LONG_MAX,
@@ -9579,7 +9579,7 @@ int btrfs_start_delalloc_snapshot(struct btrfs_root *root)
if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
return -EROFS;
- return start_delalloc_inodes(root, &wbc, true, false);
+ return start_delalloc_inodes(root, &wbc, true, in_reclaim_context);
}
int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, u64 nr,
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 24c4d059cfab..9d5dfcec22de 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1030,7 +1030,7 @@ static noinline int btrfs_mksnapshot(const struct path *parent,
*/
btrfs_drew_read_lock(&root->snapshot_lock);
- ret = btrfs_start_delalloc_snapshot(root);
+ ret = btrfs_start_delalloc_snapshot(root, false);
if (ret)
goto out;
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 95a39d535a82..bc1feb97698c 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -3704,7 +3704,7 @@ static int try_flush_qgroup(struct btrfs_root *root)
return 0;
}
- ret = btrfs_start_delalloc_snapshot(root);
+ ret = btrfs_start_delalloc_snapshot(root, true);
if (ret < 0)
goto out;
btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 3e7bb24eb227..d86b4d13cae4 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -7207,7 +7207,7 @@ static int flush_delalloc_roots(struct send_ctx *sctx)
int i;
if (root) {
- ret = btrfs_start_delalloc_snapshot(root);
+ ret = btrfs_start_delalloc_snapshot(root, false);
if (ret)
return ret;
btrfs_wait_ordered_extents(root, U64_MAX, 0, U64_MAX);
@@ -7215,7 +7215,7 @@ static int flush_delalloc_roots(struct send_ctx *sctx)
for (i = 0; i < sctx->clone_roots_cnt; i++) {
root = sctx->clone_roots[i].root;
- ret = btrfs_start_delalloc_snapshot(root);
+ ret = btrfs_start_delalloc_snapshot(root, false);
if (ret)
return ret;
btrfs_wait_ordered_extents(root, U64_MAX, 0, U64_MAX);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 21a5a963c70e..424b1dd3fe27 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -2045,7 +2045,7 @@ static inline int btrfs_start_delalloc_flush(struct btrfs_trans_handle *trans)
list_for_each_entry(pending, head, list) {
int ret;
- ret = btrfs_start_delalloc_snapshot(pending->root);
+ ret = btrfs_start_delalloc_snapshot(pending->root, false);
if (ret)
return ret;
}
--
2.40.4
From: Sean Christopherson <seanjc(a)google.com>
[ Upstream commit 17bcd714426386fda741a4bccd96a2870179344b ]
Free vCPUs before freeing any VM state, as both SVM and VMX may access
VM state when "freeing" a vCPU that is currently "in" L2, i.e. that needs
to be kicked out of nested guest mode.
Commit 6fcee03df6a1 ("KVM: x86: avoid loading a vCPU after .vm_destroy was
called") partially fixed the issue, but for unknown reasons only moved the
MMU unloading before VM destruction. Complete the change, and free all
vCPU state prior to destroying VM state, as nVMX accesses even more state
than nSVM.
In addition to the AVIC, KVM can hit a use-after-free on MSR filters:
kvm_msr_allowed+0x4c/0xd0
__kvm_set_msr+0x12d/0x1e0
kvm_set_msr+0x19/0x40
load_vmcs12_host_state+0x2d8/0x6e0 [kvm_intel]
nested_vmx_vmexit+0x715/0xbd0 [kvm_intel]
nested_vmx_free_vcpu+0x33/0x50 [kvm_intel]
vmx_free_vcpu+0x54/0xc0 [kvm_intel]
kvm_arch_vcpu_destroy+0x28/0xf0
kvm_vcpu_destroy+0x12/0x50
kvm_arch_destroy_vm+0x12c/0x1c0
kvm_put_kvm+0x263/0x3c0
kvm_vm_release+0x21/0x30
and an upcoming fix to process injectable interrupts on nested VM-Exit
will access the PIC:
BUG: kernel NULL pointer dereference, address: 0000000000000090
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
CPU: 23 UID: 1000 PID: 2658 Comm: kvm-nx-lpage-re
RIP: 0010:kvm_cpu_has_extint+0x2f/0x60 [kvm]
Call Trace:
<TASK>
kvm_cpu_has_injectable_intr+0xe/0x60 [kvm]
nested_vmx_vmexit+0x2d7/0xdf0 [kvm_intel]
nested_vmx_free_vcpu+0x40/0x50 [kvm_intel]
vmx_vcpu_free+0x2d/0x80 [kvm_intel]
kvm_arch_vcpu_destroy+0x2d/0x130 [kvm]
kvm_destroy_vcpus+0x8a/0x100 [kvm]
kvm_arch_destroy_vm+0xa7/0x1d0 [kvm]
kvm_destroy_vm+0x172/0x300 [kvm]
kvm_vcpu_release+0x31/0x50 [kvm]
Inarguably, both nSVM and nVMX need to be fixed, but punt on those
cleanups for the moment. Conceptually, vCPUs should be freed before VM
state. Assets like the I/O APIC and PIC _must_ be allocated before vCPUs
are created, so it stands to reason that they must be freed _after_ vCPUs
are destroyed.
Reported-by: Aaron Lewis <aaronlewis(a)google.com>
Closes: https://lore.kernel.org/all/20240703175618.2304869-2-aaronlewis@google.com
Cc: Jim Mattson <jmattson(a)google.com>
Cc: Yan Zhao <yan.y.zhao(a)intel.com>
Cc: Rick P Edgecombe <rick.p.edgecombe(a)intel.com>
Cc: Kai Huang <kai.huang(a)intel.com>
Cc: Isaku Yamahata <isaku.yamahata(a)intel.com>
Signed-off-by: Sean Christopherson <seanjc(a)google.com>
Signed-off-by: Kevin Cheng <chengkev(a)google.com>
---
arch/x86/kvm/x86.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f378d479fea3f..7f91b11e6f0ec 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12888,11 +12888,11 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
mutex_unlock(&kvm->slots_lock);
}
kvm_unload_vcpu_mmus(kvm);
+ kvm_destroy_vcpus(kvm);
kvm_x86_call(vm_destroy)(kvm);
kvm_free_msr_filter(srcu_dereference_check(kvm->arch.msr_filter, &kvm->srcu, 1));
kvm_pic_destroy(kvm);
kvm_ioapic_destroy(kvm);
- kvm_destroy_vcpus(kvm);
kvfree(rcu_dereference_check(kvm->arch.apic_map, 1));
kfree(srcu_dereference_check(kvm->arch.pmu_event_filter, &kvm->srcu, 1));
kvm_mmu_uninit_vm(kvm);
--
2.50.1.470.g6ba607880d-goog
From: Liu Shixin <liushixin2(a)huawei.com>
commit f1897f2f08b28ae59476d8b73374b08f856973af upstream.
syzkaller reported such a BUG_ON():
------------[ cut here ]------------
kernel BUG at mm/khugepaged.c:1835!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
...
CPU: 6 UID: 0 PID: 8009 Comm: syz.15.106 Kdump: loaded Tainted: G W 6.13.0-rc6 #22
Tainted: [W]=WARN
Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : collapse_file+0xa44/0x1400
lr : collapse_file+0x88/0x1400
sp : ffff80008afe3a60
...
Call trace:
collapse_file+0xa44/0x1400 (P)
hpage_collapse_scan_file+0x278/0x400
madvise_collapse+0x1bc/0x678
madvise_vma_behavior+0x32c/0x448
madvise_walk_vmas.constprop.0+0xbc/0x140
do_madvise.part.0+0xdc/0x2c8
__arm64_sys_madvise+0x68/0x88
invoke_syscall+0x50/0x120
el0_svc_common.constprop.0+0xc8/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x34/0x128
el0t_64_sync_handler+0xc8/0xd0
el0t_64_sync+0x190/0x198
This indicates that the pgoff is unaligned. After analysis, I confirm the
vma is mapped to /dev/zero. Such a vma certainly has vm_file, but it is
set to anonymous by mmap_zero(). So even if it's mmapped by 2m-unaligned,
it can pass the check in thp_vma_allowable_order() as it is an
anonymous-mmap, but then be collapsed as a file-mmap.
It seems the problem has existed for a long time, but actually, since we
have khugepaged_max_ptes_none check before, we will skip collapse it as it
is /dev/zero and so has no present page. But commit d8ea7cc8547c limit
the check for only khugepaged, so the BUG_ON() can be triggered by
madvise_collapse().
Add vma_is_anonymous() check to make such vma be processed by
hpage_collapse_scan_pmd().
Link: https://lkml.kernel.org/r/20250111034511.2223353-1-liushixin2@huawei.com
Fixes: d8ea7cc8547c ("mm/khugepaged: add flag to predicate khugepaged-only behavior")
Signed-off-by: Liu Shixin <liushixin2(a)huawei.com>
Reviewed-by: Yang Shi <yang(a)os.amperecomputing.com>
Acked-by: David Hildenbrand <david(a)redhat.com>
Cc: Chengming Zhou <chengming.zhou(a)linux.dev>
Cc: Johannes Weiner <hannes(a)cmpxchg.org>
Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com>
Cc: Mattew Wilcox <willy(a)infradead.org>
Cc: Muchun Song <muchun.song(a)linux.dev>
Cc: Nanyong Sun <sunnanyong(a)huawei.com>
Cc: Qi Zheng <zhengqi.arch(a)bytedance.com>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
[acsjakub: backport, clean apply]
Cc: Jakub Acs <acsjakub(a)amazon.de>
Cc: linux-mm(a)kvack.org
---
Ran into the crash with syzkaller, backporting this patch works - the
reproducer no longer crashes.
Please let me know if there was a reason not to backport.
mm/khugepaged.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index b538c3d48386..abd5764e4864 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -2404,7 +2404,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result,
VM_BUG_ON(khugepaged_scan.address < hstart ||
khugepaged_scan.address + HPAGE_PMD_SIZE >
hend);
- if (IS_ENABLED(CONFIG_SHMEM) && vma->vm_file) {
+ if (IS_ENABLED(CONFIG_SHMEM) && !vma_is_anonymous(vma)) {
struct file *file = get_file(vma->vm_file);
pgoff_t pgoff = linear_page_index(vma,
khugepaged_scan.address);
@@ -2750,7 +2750,7 @@ int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
mmap_assert_locked(mm);
memset(cc->node_load, 0, sizeof(cc->node_load));
nodes_clear(cc->alloc_nmask);
- if (IS_ENABLED(CONFIG_SHMEM) && vma->vm_file) {
+ if (IS_ENABLED(CONFIG_SHMEM) && !vma_is_anonymous(vma)) {
struct file *file = get_file(vma->vm_file);
pgoff_t pgoff = linear_page_index(vma, addr);
--
2.47.3
Amazon Web Services Development Center Germany GmbH
Tamara-Danz-Str. 13
10243 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B
Sitz: Berlin
Ust-ID: DE 365 538 597
From: Liu Shixin <liushixin2(a)huawei.com>
commit f1897f2f08b28ae59476d8b73374b08f856973af upstream.
syzkaller reported such a BUG_ON():
------------[ cut here ]------------
kernel BUG at mm/khugepaged.c:1835!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
...
CPU: 6 UID: 0 PID: 8009 Comm: syz.15.106 Kdump: loaded Tainted: G W 6.13.0-rc6 #22
Tainted: [W]=WARN
Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : collapse_file+0xa44/0x1400
lr : collapse_file+0x88/0x1400
sp : ffff80008afe3a60
...
Call trace:
collapse_file+0xa44/0x1400 (P)
hpage_collapse_scan_file+0x278/0x400
madvise_collapse+0x1bc/0x678
madvise_vma_behavior+0x32c/0x448
madvise_walk_vmas.constprop.0+0xbc/0x140
do_madvise.part.0+0xdc/0x2c8
__arm64_sys_madvise+0x68/0x88
invoke_syscall+0x50/0x120
el0_svc_common.constprop.0+0xc8/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x34/0x128
el0t_64_sync_handler+0xc8/0xd0
el0t_64_sync+0x190/0x198
This indicates that the pgoff is unaligned. After analysis, I confirm the
vma is mapped to /dev/zero. Such a vma certainly has vm_file, but it is
set to anonymous by mmap_zero(). So even if it's mmapped by 2m-unaligned,
it can pass the check in thp_vma_allowable_order() as it is an
anonymous-mmap, but then be collapsed as a file-mmap.
It seems the problem has existed for a long time, but actually, since we
have khugepaged_max_ptes_none check before, we will skip collapse it as it
is /dev/zero and so has no present page. But commit d8ea7cc8547c limit
the check for only khugepaged, so the BUG_ON() can be triggered by
madvise_collapse().
Add vma_is_anonymous() check to make such vma be processed by
hpage_collapse_scan_pmd().
Link: https://lkml.kernel.org/r/20250111034511.2223353-1-liushixin2@huawei.com
Fixes: d8ea7cc8547c ("mm/khugepaged: add flag to predicate khugepaged-only behavior")
Signed-off-by: Liu Shixin <liushixin2(a)huawei.com>
Reviewed-by: Yang Shi <yang(a)os.amperecomputing.com>
Acked-by: David Hildenbrand <david(a)redhat.com>
Cc: Chengming Zhou <chengming.zhou(a)linux.dev>
Cc: Johannes Weiner <hannes(a)cmpxchg.org>
Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com>
Cc: Mattew Wilcox <willy(a)infradead.org>
Cc: Muchun Song <muchun.song(a)linux.dev>
Cc: Nanyong Sun <sunnanyong(a)huawei.com>
Cc: Qi Zheng <zhengqi.arch(a)bytedance.com>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
[acsjakub: backport, clean apply]
Cc: Jakub Acs <acsjakub(a)amazon.de>
Cc: linux-mm(a)kvack.org
---
Ran into the crash with syzkaller, backporting this patch works - the
reproducer no longer crashes.
Please let me know if there was a reason not to backport.
mm/khugepaged.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index b538c3d48386..abd5764e4864 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -2404,7 +2404,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result,
VM_BUG_ON(khugepaged_scan.address < hstart ||
khugepaged_scan.address + HPAGE_PMD_SIZE >
hend);
- if (IS_ENABLED(CONFIG_SHMEM) && vma->vm_file) {
+ if (IS_ENABLED(CONFIG_SHMEM) && !vma_is_anonymous(vma)) {
struct file *file = get_file(vma->vm_file);
pgoff_t pgoff = linear_page_index(vma,
khugepaged_scan.address);
@@ -2750,7 +2750,7 @@ int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
mmap_assert_locked(mm);
memset(cc->node_load, 0, sizeof(cc->node_load));
nodes_clear(cc->alloc_nmask);
- if (IS_ENABLED(CONFIG_SHMEM) && vma->vm_file) {
+ if (IS_ENABLED(CONFIG_SHMEM) && !vma_is_anonymous(vma)) {
struct file *file = get_file(vma->vm_file);
pgoff_t pgoff = linear_page_index(vma, addr);
--
2.47.3
Amazon Web Services Development Center Germany GmbH
Tamara-Danz-Str. 13
10243 Berlin
Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss
Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B
Sitz: Berlin
Ust-ID: DE 365 538 597
From: Ming Lei <ming.lei(a)redhat.com>
[ Upstream commit a647a524a46736786c95cdb553a070322ca096e3 ]
rq_qos framework is only applied on request based driver, so:
1) rq_qos_done_bio() needn't to be called for bio based driver
2) rq_qos_done_bio() needn't to be called for bio which isn't tracked,
such as bios ended from error handling code.
Especially in bio_endio():
1) request queue is referred via bio->bi_bdev->bd_disk->queue, which
may be gone since request queue refcount may not be held in above two
cases
2) q->rq_qos may be freed in blk_cleanup_queue() when calling into
__rq_qos_done_bio()
Fix the potential kernel panic by not calling rq_qos_ops->done_bio if
the bio isn't tracked. This way is safe because both ioc_rqos_done_bio()
and blkcg_iolatency_done_bio() are nop if the bio isn't tracked.
Reported-by: Yu Kuai <yukuai3(a)huawei.com>
Cc: tj(a)kernel.org
Signed-off-by: Ming Lei <ming.lei(a)redhat.com>
Reviewed-by: Christoph Hellwig <hch(a)lst.de>
Acked-by: Tejun Heo <tj(a)kernel.org>
Link: https://lore.kernel.org/r/20210924110704.1541818-1-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe(a)kernel.dk>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
[Shivani: Modified to apply on 5.10.y]
Signed-off-by: Shivani Agarwal <shivani.agarwal(a)broadcom.com>
---
block/bio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/block/bio.c b/block/bio.c
index 88a09c31095f..7851f54edc76 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1430,7 +1430,7 @@ void bio_endio(struct bio *bio)
if (!bio_integrity_endio(bio))
return;
- if (bio->bi_disk)
+ if (bio->bi_disk && bio_flagged(bio, BIO_TRACKED))
rq_qos_done_bio(bio->bi_disk->queue, bio);
/*
--
2.40.4
From: Srinivasan Shanmugam <srinivasan.shanmugam(a)amd.com>
commit ac2140449184a26eac99585b7f69814bd3ba8f2d upstream.
This commit addresses a potential null pointer dereference issue in the
`dcn32_acquire_idle_pipe_for_head_pipe_in_layer` function. The issue
could occur when `head_pipe` is null.
The fix adds a check to ensure `head_pipe` is not null before asserting
it. If `head_pipe` is null, the function returns NULL to prevent a
potential null pointer dereference.
Reported by smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn32/dcn32_resource.c:2690 dcn32_acquire_idle_pipe_for_head_pipe_in_layer() error: we previously assumed 'head_pipe' could be null (see line 2681)
Cc: Tom Chung <chiahsuan.chung(a)amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira(a)amd.com>
Cc: Roman Li <roman.li(a)amd.com>
Cc: Alex Hung <alex.hung(a)amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai(a)amd.com>
Cc: Harry Wentland <harry.wentland(a)amd.com>
Cc: Hamza Mahfooz <hamza.mahfooz(a)amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam(a)amd.com>
Reviewed-by: Tom Chung <chiahsuan.chung(a)amd.com>
Signed-off-by: Alex Deucher <alexander.deucher(a)amd.com>
[ Daniil: dcn32 was moved from drivers/gpu/drm/amd/display/dc to
drivers/gpu/drm/amd/display/dc/resource since commit
8b8eed05a1c6 ("drm/amd/display: Refactor resource into component directory").
The path is changed accordingly to apply the patch on 6.1.y. and 6.6.y ]
Signed-off-by: Daniil Dulov <d.dulov(a)aladdin.ru>
---
Backport fix for CVE-2024-49918
drivers/gpu/drm/amd/display/dc/dcn32/dcn32_resource.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_resource.c b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_resource.c
index 1b1534ffee9f..591c3166a468 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_resource.c
@@ -2563,8 +2563,10 @@ struct pipe_ctx *dcn32_acquire_idle_pipe_for_head_pipe_in_layer(
struct resource_context *old_ctx = &stream->ctx->dc->current_state->res_ctx;
int head_index;
- if (!head_pipe)
+ if (!head_pipe) {
ASSERT(0);
+ return NULL;
+ }
/*
* Modified from dcn20_acquire_idle_pipe_for_layer
--
2.34.1
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 4ff12d82dac119b4b99b5a78b5af3bf2474c0a36
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025072801-game-appendix-1d20@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 4ff12d82dac119b4b99b5a78b5af3bf2474c0a36 Mon Sep 17 00:00:00 2001
From: Haoxiang Li <haoxiang_li2024(a)163.com>
Date: Thu, 3 Jul 2025 17:52:32 +0800
Subject: [PATCH] ice: Fix a null pointer dereference in
ice_copy_and_init_pkg()
Add check for the return value of devm_kmemdup()
to prevent potential null pointer dereference.
Fixes: c76488109616 ("ice: Implement Dynamic Device Personalization (DDP) download")
Cc: stable(a)vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024(a)163.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski(a)linux.intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov(a)intel.com>
Reviewed-by: Simon Horman <horms(a)kernel.org>
Tested-by: Rinitha S <sx.rinitha(a)intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen(a)intel.com>
diff --git a/drivers/net/ethernet/intel/ice/ice_ddp.c b/drivers/net/ethernet/intel/ice/ice_ddp.c
index 59323c019544..351824dc3c62 100644
--- a/drivers/net/ethernet/intel/ice/ice_ddp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ddp.c
@@ -2301,6 +2301,8 @@ enum ice_ddp_state ice_copy_and_init_pkg(struct ice_hw *hw, const u8 *buf,
return ICE_DDP_PKG_ERR;
buf_copy = devm_kmemdup(ice_hw_to_dev(hw), buf, len, GFP_KERNEL);
+ if (!buf_copy)
+ return ICE_DDP_PKG_ERR;
state = ice_init_pkg(hw, buf_copy, len);
if (!ice_is_init_pkg_successful(state)) {
The patch below does not apply to the 5.10-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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 4ff12d82dac119b4b99b5a78b5af3bf2474c0a36
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025072801-groove-marauding-e4a9@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 4ff12d82dac119b4b99b5a78b5af3bf2474c0a36 Mon Sep 17 00:00:00 2001
From: Haoxiang Li <haoxiang_li2024(a)163.com>
Date: Thu, 3 Jul 2025 17:52:32 +0800
Subject: [PATCH] ice: Fix a null pointer dereference in
ice_copy_and_init_pkg()
Add check for the return value of devm_kmemdup()
to prevent potential null pointer dereference.
Fixes: c76488109616 ("ice: Implement Dynamic Device Personalization (DDP) download")
Cc: stable(a)vger.kernel.org
Signed-off-by: Haoxiang Li <haoxiang_li2024(a)163.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski(a)linux.intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov(a)intel.com>
Reviewed-by: Simon Horman <horms(a)kernel.org>
Tested-by: Rinitha S <sx.rinitha(a)intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen(a)intel.com>
diff --git a/drivers/net/ethernet/intel/ice/ice_ddp.c b/drivers/net/ethernet/intel/ice/ice_ddp.c
index 59323c019544..351824dc3c62 100644
--- a/drivers/net/ethernet/intel/ice/ice_ddp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ddp.c
@@ -2301,6 +2301,8 @@ enum ice_ddp_state ice_copy_and_init_pkg(struct ice_hw *hw, const u8 *buf,
return ICE_DDP_PKG_ERR;
buf_copy = devm_kmemdup(ice_hw_to_dev(hw), buf, len, GFP_KERNEL);
+ if (!buf_copy)
+ return ICE_DDP_PKG_ERR;
state = ice_init_pkg(hw, buf_copy, len);
if (!ice_is_init_pkg_successful(state)) {