When a mailbox message is received, the driver is checking for a non 0
datalen in the controlq descriptor. If it is valid, the payload is
attached to the ctlq message to give to the upper layer. However, the
payload response size given to the upper layer was taken from the buffer
metadata which is _always_ the max buffer size. This meant the API was
returning 4K as the payload size for all messages. This went unnoticed
since the virtchnl exchange response logic was checking for a response
size less than 0 (error), not less than exact size, or not greater than
or equal to the max mailbox buffer size (4K). All of these checks will
pass in the success case since the size provided is always 4K. However,
this breaks anyone that wants to validate the exact response size.
Fetch the actual payload length from the value provided in the
descriptor data_len field (instead of the buffer metadata).
Unfortunately, this means we lose some extra error parsing for variable
sized virtchnl responses such as create vport and get ptypes. However,
the original checks weren't really helping anyways since the size was
_always_ 4K.
Fixes: 34c21fa894a1 ("idpf: implement virtchnl transaction manager")
Cc: stable(a)vger.kernel.org # 6.9+
Signed-off-by: Joshua Hay <joshua.a.hay(a)intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel(a)intel.com>
---
drivers/net/ethernet/intel/idpf/idpf_virtchnl.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
index 70986e12da28..3c0f97650d72 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_virtchnl.c
@@ -666,7 +666,7 @@ idpf_vc_xn_forward_reply(struct idpf_adapter *adapter,
if (ctlq_msg->data_len) {
payload = ctlq_msg->ctx.indirect.payload->va;
- payload_size = ctlq_msg->ctx.indirect.payload->size;
+ payload_size = ctlq_msg->data_len;
}
xn->reply_sz = payload_size;
@@ -1295,10 +1295,6 @@ int idpf_send_create_vport_msg(struct idpf_adapter *adapter,
err = reply_sz;
goto free_vport_params;
}
- if (reply_sz < IDPF_CTLQ_MAX_BUF_LEN) {
- err = -EIO;
- goto free_vport_params;
- }
return 0;
@@ -2602,9 +2598,6 @@ int idpf_send_get_rx_ptype_msg(struct idpf_vport *vport)
if (reply_sz < 0)
return reply_sz;
- if (reply_sz < IDPF_CTLQ_MAX_BUF_LEN)
- return -EIO;
-
ptypes_recvd += le16_to_cpu(ptype_info->num_ptypes);
if (ptypes_recvd > max_ptype)
return -EINVAL;
--
2.39.2
The patch titled
Subject: kselftests: mm: fix wrong __NR_userfaultfd value
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
kselftests-mm-fix-wrong-__nr_userfaultfd-value.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Muhammad Usama Anjum <usama.anjum(a)collabora.com>
Subject: kselftests: mm: fix wrong __NR_userfaultfd value
Date: Mon, 23 Sep 2024 10:38:36 +0500
grep -rnIF "#define __NR_userfaultfd"
tools/include/uapi/asm-generic/unistd.h:681:#define __NR_userfaultfd 282
arch/x86/include/generated/uapi/asm/unistd_32.h:374:#define
__NR_userfaultfd 374
arch/x86/include/generated/uapi/asm/unistd_64.h:327:#define
__NR_userfaultfd 323
arch/x86/include/generated/uapi/asm/unistd_x32.h:282:#define
__NR_userfaultfd (__X32_SYSCALL_BIT + 323)
arch/arm/include/generated/uapi/asm/unistd-eabi.h:347:#define
__NR_userfaultfd (__NR_SYSCALL_BASE + 388)
arch/arm/include/generated/uapi/asm/unistd-oabi.h:359:#define
__NR_userfaultfd (__NR_SYSCALL_BASE + 388)
include/uapi/asm-generic/unistd.h:681:#define __NR_userfaultfd 282
The number is dependent on the architecture. The above data shows that:
x86 374
x86_64 323
The value of __NR_userfaultfd was changed to 282 when asm-generic/unistd.h
was included. It makes the test to fail every time as the correct number
of this syscall on x86_64 is 323. Fix the header to asm/unistd.h.
Link: https://lkml.kernel.org/r/20240923053836.3270393-1-usama.anjum@collabora.com
Fixes: a5c6bc590094 ("selftests/mm: remove local __NR_* definitions")
Signed-off-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com>
Reviewed-by: Shuah Khan <skhan(a)linuxfoundation.org>
Reviewed-by: David Hildenbrand <david(a)redhat.com>
Cc: John Hubbard <jhubbard(a)nvidia.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
tools/testing/selftests/mm/pagemap_ioctl.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/tools/testing/selftests/mm/pagemap_ioctl.c~kselftests-mm-fix-wrong-__nr_userfaultfd-value
+++ a/tools/testing/selftests/mm/pagemap_ioctl.c
@@ -15,7 +15,7 @@
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <math.h>
-#include <asm-generic/unistd.h>
+#include <asm/unistd.h>
#include <pthread.h>
#include <sys/resource.h>
#include <assert.h>
_
Patches currently in -mm which might be from usama.anjum(a)collabora.com are
kselftests-mm-fix-wrong-__nr_userfaultfd-value.patch
The patch titled
Subject: compiler.h: specify correct attribute for .rodata..c_jump_table
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
compilerh-specify-correct-attribute-for-rodatac_jump_table.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Tiezhu Yang <yangtiezhu(a)loongson.cn>
Subject: compiler.h: specify correct attribute for .rodata..c_jump_table
Date: Tue, 24 Sep 2024 14:27:10 +0800
Currently, there is an assembler message when generating kernel/bpf/core.o
under CONFIG_OBJTOOL with LoongArch compiler toolchain:
Warning: setting incorrect section attributes for .rodata..c_jump_table
This is because the section ".rodata..c_jump_table" should be readonly,
but there is a "W" (writable) part of the flags:
$ readelf -S kernel/bpf/core.o | grep -A 1 "rodata..c"
[34] .rodata..c_j[...] PROGBITS 0000000000000000 0000d2e0
0000000000000800 0000000000000000 WA 0 0 8
There is no above issue on x86 due to the generated section flag is only
"A" (allocatable). In order to silence the warning on LoongArch, specify
the attribute like ".rodata..c_jump_table,\"a\",@progbits #" explicitly,
then the section attribute of ".rodata..c_jump_table" must be readonly
in the kernel/bpf/core.o file.
Before:
$ objdump -h kernel/bpf/core.o | grep -A 1 "rodata..c"
21 .rodata..c_jump_table 00000800 0000000000000000 0000000000000000 0000d2e0 2**3
CONTENTS, ALLOC, LOAD, RELOC, DATA
After:
$ objdump -h kernel/bpf/core.o | grep -A 1 "rodata..c"
21 .rodata..c_jump_table 00000800 0000000000000000 0000000000000000 0000d2e0 2**3
CONTENTS, ALLOC, LOAD, RELOC, READONLY, DATA
By the way, AFAICT, maybe the root cause is related with the different
compiler behavior of various archs, so to some extent this change is a
workaround for LoongArch, and also there is no effect for x86 which is the
only port supported by objtool before LoongArch with this patch.
Link: https://lkml.kernel.org/r/20240924062710.1243-1-yangtiezhu@loongson.cn
Signed-off-by: Tiezhu Yang <yangtiezhu(a)loongson.cn>
Cc: Josh Poimboeuf <jpoimboe(a)kernel.org>
Cc: Peter Zijlstra <peterz(a)infradead.org>
Cc: <stable(a)vger.kernel.org> [6.9+]
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
include/linux/compiler.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/include/linux/compiler.h~compilerh-specify-correct-attribute-for-rodatac_jump_table
+++ a/include/linux/compiler.h
@@ -133,7 +133,7 @@ void ftrace_likely_update(struct ftrace_
#define annotate_unreachable() __annotate_unreachable(__COUNTER__)
/* Annotate a C jump table to allow objtool to follow the code flow */
-#define __annotate_jump_table __section(".rodata..c_jump_table")
+#define __annotate_jump_table __section(".rodata..c_jump_table,\"a\",@progbits #")
#else /* !CONFIG_OBJTOOL */
#define annotate_reachable()
_
Patches currently in -mm which might be from yangtiezhu(a)loongson.cn are
compilerh-specify-correct-attribute-for-rodatac_jump_table.patch
The patch titled
Subject: ocfs2: fix deadlock in ocfs2_get_system_file_inode
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
ocfs2-fix-deadlock-in-ocfs2_get_system_file_inode.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Mohammed Anees <pvmohammedanees2003(a)gmail.com>
Subject: ocfs2: fix deadlock in ocfs2_get_system_file_inode
Date: Tue, 24 Sep 2024 09:32:57 +0000
syzbot has found a possible deadlock in ocfs2_get_system_file_inode [1].
The scenario is depicted here,
CPU0 CPU1
lock(&ocfs2_file_ip_alloc_sem_key);
lock(&osb->system_file_mutex);
lock(&ocfs2_file_ip_alloc_sem_key);
lock(&osb->system_file_mutex);
The function calls which could lead to this are:
CPU0
ocfs2_mknod - lock(&ocfs2_file_ip_alloc_sem_key);
.
.
.
ocfs2_get_system_file_inode - lock(&osb->system_file_mutex);
CPU1 -
ocfs2_fill_super - lock(&osb->system_file_mutex);
.
.
.
ocfs2_read_virt_blocks - lock(&ocfs2_file_ip_alloc_sem_key);
This issue can be resolved by making the down_read -> down_read_try
in the ocfs2_read_virt_blocks.
[1] https://syzkaller.appspot.com/bug?extid=e0055ea09f1f5e6fabdd
Link: https://lkml.kernel.org/r/20240924093257.7181-1-pvmohammedanees2003@gmail.c…
Signed-off-by: Mohammed Anees <pvmohammedanees2003(a)gmail.com>
Reviewed-by: Joseph Qi <joseph.qi(a)linux.alibaba.com>
Reported-by: <syzbot+e0055ea09f1f5e6fabdd(a)syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=e0055ea09f1f5e6fabdd
Tested-by: syzbot+e0055ea09f1f5e6fabdd(a)syzkaller.appspotmail.com
Cc: Mark Fasheh <mark(a)fasheh.com>
Cc: Joel Becker <jlbec(a)evilplan.org>
Cc: Junxiao Bi <junxiao.bi(a)oracle.com>
Cc: Changwei Ge <gechangwei(a)live.cn>
Cc: Gang He <ghe(a)suse.com>
Cc: Jun Piao <piaojun(a)huawei.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
fs/ocfs2/extent_map.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
--- a/fs/ocfs2/extent_map.c~ocfs2-fix-deadlock-in-ocfs2_get_system_file_inode
+++ a/fs/ocfs2/extent_map.c
@@ -973,7 +973,13 @@ int ocfs2_read_virt_blocks(struct inode
}
while (done < nr) {
- down_read(&OCFS2_I(inode)->ip_alloc_sem);
+ if (!down_read_trylock(&OCFS2_I(inode)->ip_alloc_sem)) {
+ rc = -EAGAIN;
+ mlog(ML_ERROR,
+ "Inode #%llu ip_alloc_sem is temporarily unavailable\n",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno);
+ break;
+ }
rc = ocfs2_extent_map_get_blocks(inode, v_block + done,
&p_block, &p_count, NULL);
up_read(&OCFS2_I(inode)->ip_alloc_sem);
_
Patches currently in -mm which might be from pvmohammedanees2003(a)gmail.com are
ocfs2-fix-deadlock-in-ocfs2_get_system_file_inode.patch
ocfs2-fix-typo-in-comment.patch
The patch titled
Subject: ocfs2: reserve space for inline xattr before attaching reflink tree
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
ocfs2-reserve-space-for-inline-xattr-before-attaching-reflink-tree.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Gautham Ananthakrishna <gautham.ananthakrishna(a)oracle.com>
Subject: ocfs2: reserve space for inline xattr before attaching reflink tree
Date: Wed, 18 Sep 2024 06:38:44 +0000
One of our customers reported a crash and a corrupted ocfs2 filesystem.
The crash was due to the detection of corruption. Upon troubleshooting,
the fsck -fn output showed the below corruption
[EXTENT_LIST_FREE] Extent list in owner 33080590 claims 230 as the next free chain record,
but fsck believes the largest valid value is 227. Clamp the next record value? n
The stat output from the debugfs.ocfs2 showed the following corruption
where the "Next Free Rec:" had overshot the "Count:" in the root metadata
block.
Inode: 33080590 Mode: 0640 Generation: 2619713622 (0x9c25a856)
FS Generation: 904309833 (0x35e6ac49)
CRC32: 00000000 ECC: 0000
Type: Regular Attr: 0x0 Flags: Valid
Dynamic Features: (0x16) HasXattr InlineXattr Refcounted
Extended Attributes Block: 0 Extended Attributes Inline Size: 256
User: 0 (root) Group: 0 (root) Size: 281320357888
Links: 1 Clusters: 141738
ctime: 0x66911b56 0x316edcb8 -- Fri Jul 12 06:02:30.829349048 2024
atime: 0x66911d6b 0x7f7a28d -- Fri Jul 12 06:11:23.133669517 2024
mtime: 0x66911b56 0x12ed75d7 -- Fri Jul 12 06:02:30.317552087 2024
dtime: 0x0 -- Wed Dec 31 17:00:00 1969
Refcount Block: 2777346
Last Extblk: 2886943 Orphan Slot: 0
Sub Alloc Slot: 0 Sub Alloc Bit: 14
Tree Depth: 1 Count: 227 Next Free Rec: 230
## Offset Clusters Block#
0 0 2310 2776351
1 2310 2139 2777375
2 4449 1221 2778399
3 5670 731 2779423
4 6401 566 2780447
....... .... .......
....... .... .......
The issue was in the reflink workfow while reserving space for inline
xattr. The problematic function is ocfs2_reflink_xattr_inline(). By the
time this function is called the reflink tree is already recreated at the
destination inode from the source inode. At this point, this function
reserves space for inline xattrs at the destination inode without even
checking if there is space at the root metadata block. It simply reduces
the l_count from 243 to 227 thereby making space of 256 bytes for inline
xattr whereas the inode already has extents beyond this index (in this
case upto 230), thereby causing corruption.
The fix for this is to reserve space for inline metadata at the destination
inode before the reflink tree gets recreated. The customer has verified the
fix.
Link: https://lkml.kernel.org/r/20240918063844.1830332-1-gautham.ananthakrishna@o…
Fixes: ef962df057aa ("ocfs2: xattr: fix inlined xattr reflink")
Signed-off-by: Gautham Ananthakrishna <gautham.ananthakrishna(a)oracle.com>
Reviewed-by: Joseph Qi <joseph.qi(a)linux.alibaba.com>
Cc: Mark Fasheh <mark(a)fasheh.com>
Cc: Joel Becker <jlbec(a)evilplan.org>
Cc: Junxiao Bi <junxiao.bi(a)oracle.com>
Cc: Changwei Ge <gechangwei(a)live.cn>
Cc: Gang He <ghe(a)suse.com>
Cc: Jun Piao <piaojun(a)huawei.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
fs/ocfs2/refcounttree.c | 26 ++++++++++++++++++++++++--
fs/ocfs2/xattr.c | 11 +----------
2 files changed, 25 insertions(+), 12 deletions(-)
--- a/fs/ocfs2/refcounttree.c~ocfs2-reserve-space-for-inline-xattr-before-attaching-reflink-tree
+++ a/fs/ocfs2/refcounttree.c
@@ -25,6 +25,7 @@
#include "namei.h"
#include "ocfs2_trace.h"
#include "file.h"
+#include "symlink.h"
#include <linux/bio.h>
#include <linux/blkdev.h>
@@ -4148,8 +4149,9 @@ static int __ocfs2_reflink(struct dentry
int ret;
struct inode *inode = d_inode(old_dentry);
struct buffer_head *new_bh = NULL;
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
- if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE) {
+ if (oi->ip_flags & OCFS2_INODE_SYSTEM_FILE) {
ret = -EINVAL;
mlog_errno(ret);
goto out;
@@ -4175,6 +4177,26 @@ static int __ocfs2_reflink(struct dentry
goto out_unlock;
}
+ if ((oi->ip_dyn_features & OCFS2_HAS_XATTR_FL) &&
+ (oi->ip_dyn_features & OCFS2_INLINE_XATTR_FL)) {
+ /*
+ * Adjust extent record count to reserve space for extended attribute.
+ * Inline data count had been adjusted in ocfs2_duplicate_inline_data().
+ */
+ struct ocfs2_inode_info *new_oi = OCFS2_I(new_inode);
+
+ if (!(new_oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) &&
+ !(ocfs2_inode_is_fast_symlink(new_inode))) {
+ struct ocfs2_dinode *new_di = (struct ocfs2_dinode *)new_bh->b_data;
+ struct ocfs2_dinode *old_di = (struct ocfs2_dinode *)old_bh->b_data;
+ struct ocfs2_extent_list *el = &new_di->id2.i_list;
+ int inline_size = le16_to_cpu(old_di->i_xattr_inline_size);
+
+ le16_add_cpu(&el->l_count, -(inline_size /
+ sizeof(struct ocfs2_extent_rec)));
+ }
+ }
+
ret = ocfs2_create_reflink_node(inode, old_bh,
new_inode, new_bh, preserve);
if (ret) {
@@ -4182,7 +4204,7 @@ static int __ocfs2_reflink(struct dentry
goto inode_unlock;
}
- if (OCFS2_I(inode)->ip_dyn_features & OCFS2_HAS_XATTR_FL) {
+ if (oi->ip_dyn_features & OCFS2_HAS_XATTR_FL) {
ret = ocfs2_reflink_xattrs(inode, old_bh,
new_inode, new_bh,
preserve);
--- a/fs/ocfs2/xattr.c~ocfs2-reserve-space-for-inline-xattr-before-attaching-reflink-tree
+++ a/fs/ocfs2/xattr.c
@@ -6511,16 +6511,7 @@ static int ocfs2_reflink_xattr_inline(st
}
new_oi = OCFS2_I(args->new_inode);
- /*
- * Adjust extent record count to reserve space for extended attribute.
- * Inline data count had been adjusted in ocfs2_duplicate_inline_data().
- */
- if (!(new_oi->ip_dyn_features & OCFS2_INLINE_DATA_FL) &&
- !(ocfs2_inode_is_fast_symlink(args->new_inode))) {
- struct ocfs2_extent_list *el = &new_di->id2.i_list;
- le16_add_cpu(&el->l_count, -(inline_size /
- sizeof(struct ocfs2_extent_rec)));
- }
+
spin_lock(&new_oi->ip_lock);
new_oi->ip_dyn_features |= OCFS2_HAS_XATTR_FL | OCFS2_INLINE_XATTR_FL;
new_di->i_dyn_features = cpu_to_le16(new_oi->ip_dyn_features);
_
Patches currently in -mm which might be from gautham.ananthakrishna(a)oracle.com are
ocfs2-reserve-space-for-inline-xattr-before-attaching-reflink-tree.patch
The patch titled
Subject: mm: migrate: annotate data-race in migrate_folio_unmap()
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-migrate-annotate-data-race-in-migrate_folio_unmap.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patche…
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Jeongjun Park <aha310510(a)gmail.com>
Subject: mm: migrate: annotate data-race in migrate_folio_unmap()
Date: Tue, 24 Sep 2024 22:00:53 +0900
I found a report from syzbot [1]
This report shows that the value can be changed, but in reality, the
value of __folio_set_movable() cannot be changed because it holds the
folio refcount.
Therefore, it is appropriate to add an annotate to make KCSAN
ignore that data-race.
[1]
==================================================================
BUG: KCSAN: data-race in __filemap_remove_folio / migrate_pages_batch
write to 0xffffea0004b81dd8 of 8 bytes by task 6348 on cpu 0:
page_cache_delete mm/filemap.c:153 [inline]
__filemap_remove_folio+0x1ac/0x2c0 mm/filemap.c:233
filemap_remove_folio+0x6b/0x1f0 mm/filemap.c:265
truncate_inode_folio+0x42/0x50 mm/truncate.c:178
shmem_undo_range+0x25b/0xa70 mm/shmem.c:1028
shmem_truncate_range mm/shmem.c:1144 [inline]
shmem_evict_inode+0x14d/0x530 mm/shmem.c:1272
evict+0x2f0/0x580 fs/inode.c:731
iput_final fs/inode.c:1883 [inline]
iput+0x42a/0x5b0 fs/inode.c:1909
dentry_unlink_inode+0x24f/0x260 fs/dcache.c:412
__dentry_kill+0x18b/0x4c0 fs/dcache.c:615
dput+0x5c/0xd0 fs/dcache.c:857
__fput+0x3fb/0x6d0 fs/file_table.c:439
____fput+0x1c/0x30 fs/file_table.c:459
task_work_run+0x13a/0x1a0 kernel/task_work.c:228
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
__syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
syscall_exit_to_user_mode+0xbe/0x130 kernel/entry/common.c:218
do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
read to 0xffffea0004b81dd8 of 8 bytes by task 6342 on cpu 1:
__folio_test_movable include/linux/page-flags.h:699 [inline]
migrate_folio_unmap mm/migrate.c:1199 [inline]
migrate_pages_batch+0x24c/0x1940 mm/migrate.c:1797
migrate_pages_sync mm/migrate.c:1963 [inline]
migrate_pages+0xff1/0x1820 mm/migrate.c:2072
do_mbind mm/mempolicy.c:1390 [inline]
kernel_mbind mm/mempolicy.c:1533 [inline]
__do_sys_mbind mm/mempolicy.c:1607 [inline]
__se_sys_mbind+0xf76/0x1160 mm/mempolicy.c:1603
__x64_sys_mbind+0x78/0x90 mm/mempolicy.c:1603
x64_sys_call+0x2b4d/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:238
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
value changed: 0xffff888127601078 -> 0x0000000000000000
Link: https://lkml.kernel.org/r/20240924130053.107490-1-aha310510@gmail.com
Fixes: 7e2a5e5ab217 ("mm: migrate: use __folio_test_movable()")
Signed-off-by: Jeongjun Park <aha310510(a)gmail.com>
Reported-by: syzbot <syzkaller(a)googlegroups.com>
Cc: David Hildenbrand <david(a)redhat.com>
Cc: Kefeng Wang <wangkefeng.wang(a)huawei.com>
Cc: Matthew Wilcox <willy(a)infradead.org>
Cc: Zi Yan <ziy(a)nvidia.com>
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org>
---
mm/migrate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/migrate.c~mm-migrate-annotate-data-race-in-migrate_folio_unmap
+++ a/mm/migrate.c
@@ -1196,7 +1196,7 @@ static int migrate_folio_unmap(new_folio
int rc = -EAGAIN;
int old_page_state = 0;
struct anon_vma *anon_vma = NULL;
- bool is_lru = !__folio_test_movable(src);
+ bool is_lru = data_race(!__folio_test_movable(src));
bool locked = false;
bool dst_locked = false;
_
Patches currently in -mm which might be from aha310510(a)gmail.com are
mm-migrate-annotate-data-race-in-migrate_folio_unmap.patch
mm-percpu-fix-typo-to-pcpu_alloc_noprof-description.patch