Backport of a similar change from commit 5ac9b4e935df ("lib/buildid:
Handle memfd_secret() files in build_id_parse()") to address an issue
where accessing secret memfd contents through build_id_parse() would
trigger faults.
Original report and repro can be found in [0].
[0] https://lore.kernel.org/bpf/ZwyG8Uro%2FSyTXAni@ly-workstation/
This repro will cause BUG: unable to handle kernel paging request in
build_id_parse in 5.15/6.1/6.6.
Some other discussions can be found in [1].
[1] https://lore.kernel.org/bpf/20241104175256.2327164-1-jolsa@kernel.org/T/#u
Cc: stable(a)vger.kernel.org
Fixes: 88a16a130933 ("perf: Add build id data in mmap2 event")
Signed-off-by: Chen Linxuan <chenlinxuan(a)deepin.org>
---
lib/buildid.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/lib/buildid.c b/lib/buildid.c
index 9fc46366597e..b78d119ed1f7 100644
--- a/lib/buildid.c
+++ b/lib/buildid.c
@@ -157,6 +157,12 @@ int build_id_parse(struct vm_area_struct *vma, unsigned char *build_id,
if (!vma->vm_file)
return -EINVAL;
+#ifdef CONFIG_SECRETMEM
+ /* reject secretmem folios created with memfd_secret() */
+ if (vma->vm_file->f_mapping->a_ops == &secretmem_aops)
+ return -EFAULT;
+#endif
+
page = find_get_page(vma->vm_file->f_mapping, 0);
if (!page)
return -EFAULT; /* page not mapped */
--
2.48.1
From: David Hildenbrand <david(a)redhat.com>
commit 091c1dd2d4df6edd1beebe0e5863d4034ade9572 upstream.
We currently assume that there is at least one VMA in a MM, which isn't
true.
So we might end up having find_vma() return NULL, to then de-reference
NULL. So properly handle find_vma() returning NULL.
This fixes the report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 6021 Comm: syz-executor284 Not tainted 6.12.0-rc7-syzkaller-00187-gf868cd251776 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
RIP: 0010:migrate_to_node mm/mempolicy.c:1090 [inline]
RIP: 0010:do_migrate_pages+0x403/0x6f0 mm/mempolicy.c:1194
Code: ...
RSP: 0018:ffffc9000375fd08 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffc9000375fd78 RCX: 0000000000000000
RDX: ffff88807e171300 RSI: dffffc0000000000 RDI: ffff88803390c044
RBP: ffff88807e171428 R08: 0000000000000014 R09: fffffbfff2039ef1
R10: ffffffff901cf78f R11: 0000000000000000 R12: 0000000000000003
R13: ffffc9000375fe90 R14: ffffc9000375fe98 R15: ffffc9000375fdf8
FS: 00005555919e1380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555919e1ca8 CR3: 000000007f12a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
kernel_migrate_pages+0x5b2/0x750 mm/mempolicy.c:1709
__do_sys_migrate_pages mm/mempolicy.c:1727 [inline]
__se_sys_migrate_pages mm/mempolicy.c:1723 [inline]
__x64_sys_migrate_pages+0x96/0x100 mm/mempolicy.c:1723
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[akpm(a)linux-foundation.org: add unlikely()]
Link: https://lkml.kernel.org/r/20241120201151.9518-1-david@redhat.com
Fixes: 39743889aaf7 ("[PATCH] Swap Migration V5: sys_migrate_pages interface")
Signed-off-by: David Hildenbrand <david(a)redhat.com>
Reported-by: syzbot+3511625422f7aa637f0d(a)syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/673d2696.050a0220.3c9d61.012f.GAE@google.com/T/
Reviewed-by: Liam R. Howlett <Liam.Howlett(a)Oracle.com>
Reviewed-by: Christoph Lameter <cl(a)linux.com>
Cc: Liam R. Howlett <Liam.Howlett(a)Oracle.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
[ Alexey: mmap_read_lock is not used in this context, so mmap_read_unlock
is removed. Synchronization is provided by an external context in
do_migrate_pages(). ]
Signed-off-by: Alexey Panov <apanov(a)astralinux.ru>
---
v2: Clarify mmap_lock context in changes summary. Fix braces for a single
statement block. Rearrange the changes with a comment and VM_BUG_ON to
look more consistent with upstream.
mm/mempolicy.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 399d8cb48813..f60ff4727f46 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1062,13 +1062,17 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest,
nodes_clear(nmask);
node_set(source, nmask);
+ VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)));
+
+ vma = find_vma(mm, 0);
+ if (unlikely(!vma))
+ return 0;
+
/*
* This does not "check" the range but isolates all pages that
* need migration. Between passing in the full user address
* space range and MPOL_MF_DISCONTIG_OK, this call can not fail.
*/
- vma = find_vma(mm, 0);
- VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)));
queue_pages_range(mm, vma->vm_start, mm->task_size, &nmask,
flags | MPOL_MF_DISCONTIG_OK, &pagelist);
--
2.30.2
From: David Hildenbrand <david(a)redhat.com>
commit 091c1dd2d4df6edd1beebe0e5863d4034ade9572 upstream.
We currently assume that there is at least one VMA in a MM, which isn't
true.
So we might end up having find_vma() return NULL, to then de-reference
NULL. So properly handle find_vma() returning NULL.
This fixes the report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 1 UID: 0 PID: 6021 Comm: syz-executor284 Not tainted 6.12.0-rc7-syzkaller-00187-gf868cd251776 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
RIP: 0010:migrate_to_node mm/mempolicy.c:1090 [inline]
RIP: 0010:do_migrate_pages+0x403/0x6f0 mm/mempolicy.c:1194
Code: ...
RSP: 0018:ffffc9000375fd08 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffc9000375fd78 RCX: 0000000000000000
RDX: ffff88807e171300 RSI: dffffc0000000000 RDI: ffff88803390c044
RBP: ffff88807e171428 R08: 0000000000000014 R09: fffffbfff2039ef1
R10: ffffffff901cf78f R11: 0000000000000000 R12: 0000000000000003
R13: ffffc9000375fe90 R14: ffffc9000375fe98 R15: ffffc9000375fdf8
FS: 00005555919e1380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555919e1ca8 CR3: 000000007f12a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
kernel_migrate_pages+0x5b2/0x750 mm/mempolicy.c:1709
__do_sys_migrate_pages mm/mempolicy.c:1727 [inline]
__se_sys_migrate_pages mm/mempolicy.c:1723 [inline]
__x64_sys_migrate_pages+0x96/0x100 mm/mempolicy.c:1723
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
[akpm(a)linux-foundation.org: add unlikely()]
Link: https://lkml.kernel.org/r/20241120201151.9518-1-david@redhat.com
Fixes: 39743889aaf7 ("[PATCH] Swap Migration V5: sys_migrate_pages interface")
Signed-off-by: David Hildenbrand <david(a)redhat.com>
Reported-by: syzbot+3511625422f7aa637f0d(a)syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/673d2696.050a0220.3c9d61.012f.GAE@google.com/T/
Reviewed-by: Liam R. Howlett <Liam.Howlett(a)Oracle.com>
Reviewed-by: Christoph Lameter <cl(a)linux.com>
Cc: Liam R. Howlett <Liam.Howlett(a)Oracle.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
[ Alexey: mmap_read_lock is not used in this context, so mmap_read_unlock
is removed. Synchronization is provided by an external context in
do_migrate_pages(). find_vma(mm, 0) is the same as mm->mmap. ]
Signed-off-by: Alexey Panov <apanov(a)astralinux.ru>
---
v2: Clarify mmap_lock context in changes summary. Fix braces for a single
statement block. Rearrange the changes with a comment and VM_BUG_ON to
look more consistent with upstream.
mm/mempolicy.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 6c98585f20df..db94aec0ea17 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1067,6 +1067,7 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest,
int flags)
{
nodemask_t nmask;
+ struct vm_area_struct *vma;
LIST_HEAD(pagelist);
int err = 0;
struct migration_target_control mtc = {
@@ -1077,13 +1078,18 @@ static int migrate_to_node(struct mm_struct *mm, int source, int dest,
nodes_clear(nmask);
node_set(source, nmask);
+ VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)));
+
+ vma = find_vma(mm, 0);
+ if (unlikely(!vma))
+ return 0;
+
/*
* This does not "check" the range but isolates all pages that
* need migration. Between passing in the full user address
* space range and MPOL_MF_DISCONTIG_OK, this call can not fail.
*/
- VM_BUG_ON(!(flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)));
- queue_pages_range(mm, mm->mmap->vm_start, mm->task_size, &nmask,
+ queue_pages_range(mm, vma->vm_start, mm->task_size, &nmask,
flags | MPOL_MF_DISCONTIG_OK, &pagelist);
if (!list_empty(&pagelist)) {
--
2.30.2