fs/ocfs2/extent_map.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
Syzbot reported a BUG in ocfs2_read_virt_blocks.
------------[ cut here ]------------
kernel BUG at fs/ocfs2/extent_map.c:971!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 5221 Comm: syz-executor117 Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:ocfs2_read_virt_blocks+0xaa3/0xb20 fs/ocfs2/extent_map.c:971
Code: 8b 54 24 30 8b 4c 24 1c 4c 8b 44 24 38 45 89 e1 ff 74 24 48 e8 7e 0a 0c 00 48 83 c4 08 eb 25 e8 43 d2 34 08 e8 ee d1 0c fe 90 <0f> 0b e8 e6 d1 0c fe 4c 89 e8 45 89 e5 49 89 c4 e9 01 f7 ff ff e8
RSP: 0018:ffffc90002e2e820 EFLAGS: 00010293
RAX: ffffffff83881432 RBX: 0000000000000000 RCX: ffff88802d3e9e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90002e2e9f0 R08: ffffffff83880eae R09: 1ffffffff203781d
R10: dffffc0000000000 R11: fffffbfff203781e R12: ffff8880764d8878
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff920005c5d18
FS: 000055557cd55380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005628fd41e058 CR3: 000000002d2e6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ocfs2_read_dir_block+0x106/0x5c0 fs/ocfs2/dir.c:508
ocfs2_find_dir_space_el fs/ocfs2/dir.c:3427 [inline] // status = ocfs2_read_dir_block(dir, 0, &bh, 0);
ocfs2_prepare_dir_for_insert+0x3f2/0x5c60 fs/ocfs2/dir.c:4274
ocfs2_mknod+0xcaf/0x2b40 fs/ocfs2/namei.c:292
ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
lookup_open fs/namei.c:3595 [inline]
open_last_lookups fs/namei.c:3694 [inline]
path_openat+0x1c03/0x3590 fs/namei.c:3930
do_filp_open+0x235/0x490 fs/namei.c:3960
do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
do_sys_open fs/open.c:1430 [inline]
__do_sys_openat fs/open.c:1446 [inline]
__se_sys_openat fs/open.c:1441 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1441
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
It is because the parameter v_block passed to ocfs2_read_virt_blocks() is 0,
nr is 1, and inode->i_size is 0, and flags are also 0.
In this path, v_block, flags, and nr are fixed values that are hard coded,
so if i_size is 0, the bug will be triggered.
Therefore, it is more meaningful to check if the flags contain the READHEAD
bit when their value is non-zero.
Reported-and-tested-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
V1 -> V2: keep rc to 0 when falgs contains READHEAD
fs/ocfs2/extent_map.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index f7672472fa82..0043c2428ef2 100644
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -968,7 +968,8 @@ int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
if (((v_block + nr - 1) << inode->i_sb->s_blocksize_bits) >=
i_size_read(inode)) {
- BUG_ON(!(flags & OCFS2_BH_READAHEAD));
+ BUG_ON(flags && !(flags & OCFS2_BH_READAHEAD));
+ rc = flags ? 0 : -EIO;
goto out;
}
--
2.43.0
On 10/14/24 7:31 AM, Edward Adam Davis wrote:
> Syzbot reported a BUG in ocfs2_read_virt_blocks.
> ------------[ cut here ]------------
> kernel BUG at fs/ocfs2/extent_map.c:971!
> Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
> CPU: 1 UID: 0 PID: 5221 Comm: syz-executor117 Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
> RIP: 0010:ocfs2_read_virt_blocks+0xaa3/0xb20 fs/ocfs2/extent_map.c:971
> Code: 8b 54 24 30 8b 4c 24 1c 4c 8b 44 24 38 45 89 e1 ff 74 24 48 e8 7e 0a 0c 00 48 83 c4 08 eb 25 e8 43 d2 34 08 e8 ee d1 0c fe 90 <0f> 0b e8 e6 d1 0c fe 4c 89 e8 45 89 e5 49 89 c4 e9 01 f7 ff ff e8
> RSP: 0018:ffffc90002e2e820 EFLAGS: 00010293
> RAX: ffffffff83881432 RBX: 0000000000000000 RCX: ffff88802d3e9e00
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: ffffc90002e2e9f0 R08: ffffffff83880eae R09: 1ffffffff203781d
> R10: dffffc0000000000 R11: fffffbfff203781e R12: ffff8880764d8878
> R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff920005c5d18
> FS: 000055557cd55380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00005628fd41e058 CR3: 000000002d2e6000 CR4: 00000000003526f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> <TASK>
> ocfs2_read_dir_block+0x106/0x5c0 fs/ocfs2/dir.c:508
> ocfs2_find_dir_space_el fs/ocfs2/dir.c:3427 [inline] // status = ocfs2_read_dir_block(dir, 0, &bh, 0);
Keep the original stacks is enough.
> ocfs2_prepare_dir_for_insert+0x3f2/0x5c60 fs/ocfs2/dir.c:4274
> ocfs2_mknod+0xcaf/0x2b40 fs/ocfs2/namei.c:292
> ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
> lookup_open fs/namei.c:3595 [inline]
> open_last_lookups fs/namei.c:3694 [inline]
> path_openat+0x1c03/0x3590 fs/namei.c:3930
> do_filp_open+0x235/0x490 fs/namei.c:3960
> do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
> do_sys_open fs/open.c:1430 [inline]
> __do_sys_openat fs/open.c:1446 [inline]
> __se_sys_openat fs/open.c:1441 [inline]
> __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> It is because the parameter v_block passed to ocfs2_read_virt_blocks() is 0,
> nr is 1, and inode->i_size is 0, and flags are also 0.
> In this path, v_block, flags, and nr are fixed values that are hard coded,
> so if i_size is 0, the bug will be triggered.
> Therefore, it is more meaningful to check if the flags contain the READHEAD
> bit when their value is non-zero.
>
> Reported-and-tested-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> ---
> V1 -> V2: keep rc to 0 when falgs contains READHEAD
>
> fs/ocfs2/extent_map.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
> index f7672472fa82..0043c2428ef2 100644
> --- a/fs/ocfs2/extent_map.c
> +++ b/fs/ocfs2/extent_map.c
> @@ -968,7 +968,8 @@ int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
>
> if (((v_block + nr - 1) << inode->i_sb->s_blocksize_bits) >=
> i_size_read(inode)) {
> - BUG_ON(!(flags & OCFS2_BH_READAHEAD));
> + BUG_ON(flags && !(flags & OCFS2_BH_READAHEAD));
I don't think this is a right fix.
As you described in commit log, I think the root cause is the inode size
is 0, which mean no blocks actually.
So it seems we have to add a sanity check for this case.
Thanks,
Joseph
> + rc = flags ? 0 : -EIO;
> goto out;
> }
>
Syzbot reported a BUG in ocfs2_read_virt_blocks.
------------[ cut here ]------------
kernel BUG at fs/ocfs2/extent_map.c:971!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 5221 Comm: syz-executor117 Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:ocfs2_read_virt_blocks+0xaa3/0xb20 fs/ocfs2/extent_map.c:971
Code: 8b 54 24 30 8b 4c 24 1c 4c 8b 44 24 38 45 89 e1 ff 74 24 48 e8 7e 0a 0c 00 48 83 c4 08 eb 25 e8 43 d2 34 08 e8 ee d1 0c fe 90 <0f> 0b e8 e6 d1 0c fe 4c 89 e8 45 89 e5 49 89 c4 e9 01 f7 ff ff e8
RSP: 0018:ffffc90002e2e820 EFLAGS: 00010293
RAX: ffffffff83881432 RBX: 0000000000000000 RCX: ffff88802d3e9e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90002e2e9f0 R08: ffffffff83880eae R09: 1ffffffff203781d
R10: dffffc0000000000 R11: fffffbfff203781e R12: ffff8880764d8878
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff920005c5d18
FS: 000055557cd55380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005628fd41e058 CR3: 000000002d2e6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ocfs2_read_dir_block+0x106/0x5c0 fs/ocfs2/dir.c:508
ocfs2_find_dir_space_el fs/ocfs2/dir.c:3427 [inline] // status = ocfs2_read_dir_block(dir, 0, &bh, 0);
ocfs2_prepare_dir_for_insert+0x3f2/0x5c60 fs/ocfs2/dir.c:4274
ocfs2_mknod+0xcaf/0x2b40 fs/ocfs2/namei.c:292
ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
lookup_open fs/namei.c:3595 [inline]
open_last_lookups fs/namei.c:3694 [inline]
path_openat+0x1c03/0x3590 fs/namei.c:3930
do_filp_open+0x235/0x490 fs/namei.c:3960
do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
do_sys_open fs/open.c:1430 [inline]
__do_sys_openat fs/open.c:1446 [inline]
__se_sys_openat fs/open.c:1441 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1441
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
In this path, v_block(0), flags(0), and nr(1) are fixed values that are
hard coded, so if i_size is 0, the bug will be triggered.
Reported-and-tested-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
V1 -> V2: keep rc to 0 when falgs contains READHEAD
V2 -> V3: check i_size only and alert subject and comments
fs/ocfs2/extent_map.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
#syz test
diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index f7672472fa82..29d27a70dbdd 100644
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -961,13 +961,17 @@ int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
int rc = 0;
u64 p_block, p_count;
int i, count, done = 0;
+ loff_t i_size = i_size_read(inode);
trace_ocfs2_read_virt_blocks(
inode, (unsigned long long)v_block, nr, bhs, flags,
validate);
+ if (!i_size)
+ return -EINVAL;
+
if (((v_block + nr - 1) << inode->i_sb->s_blocksize_bits) >=
- i_size_read(inode)) {
+ i_size) {
BUG_ON(!(flags & OCFS2_BH_READAHEAD));
goto out;
}
--
2.43.0
On 10/14/24 7:47 PM, Edward Adam Davis wrote:
> Syzbot reported a BUG in ocfs2_read_virt_blocks.
> ------------[ cut here ]------------
> kernel BUG at fs/ocfs2/extent_map.c:971!
> Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
> CPU: 1 UID: 0 PID: 5221 Comm: syz-executor117 Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
> RIP: 0010:ocfs2_read_virt_blocks+0xaa3/0xb20 fs/ocfs2/extent_map.c:971
> Code: 8b 54 24 30 8b 4c 24 1c 4c 8b 44 24 38 45 89 e1 ff 74 24 48 e8 7e 0a 0c 00 48 83 c4 08 eb 25 e8 43 d2 34 08 e8 ee d1 0c fe 90 <0f> 0b e8 e6 d1 0c fe 4c 89 e8 45 89 e5 49 89 c4 e9 01 f7 ff ff e8
> RSP: 0018:ffffc90002e2e820 EFLAGS: 00010293
> RAX: ffffffff83881432 RBX: 0000000000000000 RCX: ffff88802d3e9e00
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: ffffc90002e2e9f0 R08: ffffffff83880eae R09: 1ffffffff203781d
> R10: dffffc0000000000 R11: fffffbfff203781e R12: ffff8880764d8878
> R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff920005c5d18
> FS: 000055557cd55380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00005628fd41e058 CR3: 000000002d2e6000 CR4: 00000000003526f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
> <TASK>
> ocfs2_read_dir_block+0x106/0x5c0 fs/ocfs2/dir.c:508
> ocfs2_find_dir_space_el fs/ocfs2/dir.c:3427 [inline] // status = ocfs2_read_dir_block(dir, 0, &bh, 0);
As I replied before, the comment behind seems unneeded.
> ocfs2_prepare_dir_for_insert+0x3f2/0x5c60 fs/ocfs2/dir.c:4274
> ocfs2_mknod+0xcaf/0x2b40 fs/ocfs2/namei.c:292
> ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
> lookup_open fs/namei.c:3595 [inline]
> open_last_lookups fs/namei.c:3694 [inline]
> path_openat+0x1c03/0x3590 fs/namei.c:3930
> do_filp_open+0x235/0x490 fs/namei.c:3960
> do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
> do_sys_open fs/open.c:1430 [inline]
> __do_sys_openat fs/open.c:1446 [inline]
> __se_sys_openat fs/open.c:1441 [inline]
> __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> In this path, v_block(0), flags(0), and nr(1) are fixed values that are
> hard coded, so if i_size is 0, the bug will be triggered.
>
This is not a proper commit log.
You have to convert to the user scenario, but not simply list the
parameters value that cause the issue.
> Reported-and-tested-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> ---
> V1 -> V2: keep rc to 0 when falgs contains READHEAD
> V2 -> V3: check i_size only and alert subject and comments
>
> fs/ocfs2/extent_map.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> #syz test
>
> diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
> index f7672472fa82..29d27a70dbdd 100644
> --- a/fs/ocfs2/extent_map.c
> +++ b/fs/ocfs2/extent_map.c
> @@ -961,13 +961,17 @@ int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
> int rc = 0;
> u64 p_block, p_count;
> int i, count, done = 0;
> + loff_t i_size = i_size_read(inode);
>
> trace_ocfs2_read_virt_blocks(
> inode, (unsigned long long)v_block, nr, bhs, flags,
> validate);
>
> + if (!i_size)
> + return -EINVAL;
> +
Take a more consideration, inode size 0 doesn't mean it has no blocks,
since we have a case that fallocate with KEEP_SIZE.
Could you please check inode->i_blocks in above coredump?
Thanks,
Joseph
> if (((v_block + nr - 1) << inode->i_sb->s_blocksize_bits) >=
> - i_size_read(inode)) {
> + i_size) {
> BUG_ON(!(flags & OCFS2_BH_READAHEAD));
> goto out;
> }
On Wed, 16 Oct 2024 10:06:27 +0800, Joseph Qi wrote: > > Reported-and-tested-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com > > Closes: https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7 > > Signed-off-by: Edward Adam Davis <eadavis@qq.com> > > --- > > V1 -> V2: keep rc to 0 when falgs contains READHEAD > > V2 -> V3: check i_size only and alert subject and comments > > > > fs/ocfs2/extent_map.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > #syz test > > > > diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c > > index f7672472fa82..29d27a70dbdd 100644 > > --- a/fs/ocfs2/extent_map.c > > +++ b/fs/ocfs2/extent_map.c > > @@ -961,13 +961,17 @@ int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr, > > int rc = 0; > > u64 p_block, p_count; > > int i, count, done = 0; > > + loff_t i_size = i_size_read(inode); > > > > trace_ocfs2_read_virt_blocks( > > inode, (unsigned long long)v_block, nr, bhs, flags, > > validate); > > > > + if (!i_size) > > + return -EINVAL; > > + > > Take a more consideration, inode size 0 doesn't mean it has no blocks, > since we have a case that fallocate with KEEP_SIZE. > Could you please check inode->i_blocks in above coredump? I have previously verified the value of inode->i_blocks in my testing environment, which is 0. BR, Edward
On 10/16/24 11:52 AM, Edward Adam Davis wrote: > On Wed, 16 Oct 2024 10:06:27 +0800, Joseph Qi wrote: >>> Reported-and-tested-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com >>> Closes: https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7 >>> Signed-off-by: Edward Adam Davis <eadavis@qq.com> >>> --- >>> V1 -> V2: keep rc to 0 when falgs contains READHEAD >>> V2 -> V3: check i_size only and alert subject and comments >>> >>> fs/ocfs2/extent_map.c | 6 +++++- >>> 1 file changed, 5 insertions(+), 1 deletion(-) >>> >>> #syz test >>> >>> diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c >>> index f7672472fa82..29d27a70dbdd 100644 >>> --- a/fs/ocfs2/extent_map.c >>> +++ b/fs/ocfs2/extent_map.c >>> @@ -961,13 +961,17 @@ int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr, >>> int rc = 0; >>> u64 p_block, p_count; >>> int i, count, done = 0; >>> + loff_t i_size = i_size_read(inode); >>> >>> trace_ocfs2_read_virt_blocks( >>> inode, (unsigned long long)v_block, nr, bhs, flags, >>> validate); >>> >>> + if (!i_size) >>> + return -EINVAL; >>> + >> >> Take a more consideration, inode size 0 doesn't mean it has no blocks, >> since we have a case that fallocate with KEEP_SIZE. >> Could you please check inode->i_blocks in above coredump? > I have previously verified the value of inode->i_blocks in my testing environment, which is 0. > So it seems the check condition should be: (v_block + nr) > (inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9))
On Wed, 16 Oct 2024 19:08:26 +0800, Joseph Qi wrote:
> On 10/16/24 11:52 AM, Edward Adam Davis wrote:
> > On Wed, 16 Oct 2024 10:06:27 +0800, Joseph Qi wrote:
> >>> Reported-and-tested-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com
> >>> Closes: https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
> >>> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> >>> ---
> >>> V1 -> V2: keep rc to 0 when falgs contains READHEAD
> >>> V2 -> V3: check i_size only and alert subject and comments
> >>>
> >>> fs/ocfs2/extent_map.c | 6 +++++-
> >>> 1 file changed, 5 insertions(+), 1 deletion(-)
> >>>
> >>> #syz test
> >>>
> >>> diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
> >>> index f7672472fa82..29d27a70dbdd 100644
> >>> --- a/fs/ocfs2/extent_map.c
> >>> +++ b/fs/ocfs2/extent_map.c
> >>> @@ -961,13 +961,17 @@ int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
> >>> int rc = 0;
> >>> u64 p_block, p_count;
> >>> int i, count, done = 0;
> >>> + loff_t i_size = i_size_read(inode);
> >>>
> >>> trace_ocfs2_read_virt_blocks(
> >>> inode, (unsigned long long)v_block, nr, bhs, flags,
> >>> validate);
> >>>
> >>> + if (!i_size)
> >>> + return -EINVAL;
> >>> +
> >>
> >> Take a more consideration, inode size 0 doesn't mean it has no blocks,
> >> since we have a case that fallocate with KEEP_SIZE.
> >> Could you please check inode->i_blocks in above coredump?
> > I have previously verified the value of inode->i_blocks in my testing environment, which is 0.
> >
> So it seems the check condition should be:
>
> (v_block + nr) > (inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9))
Do you mean like this?
diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index f7672472fa82..9613cd356ac5 100644
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -966,6 +966,9 @@ int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
inode, (unsigned long long)v_block, nr, bhs, flags,
validate);
+ if ((v_block + nr) > (inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9)))
+ return -EINVAL;
+
if (((v_block + nr - 1) << inode->i_sb->s_blocksize_bits) >=
i_size_read(inode)) {
BUG_ON(!(flags & OCFS2_BH_READAHEAD));
BR,
Edward
On 10/16/24 7:57 PM, Edward Adam Davis wrote:
> On Wed, 16 Oct 2024 19:08:26 +0800, Joseph Qi wrote:
>> On 10/16/24 11:52 AM, Edward Adam Davis wrote:
>>> On Wed, 16 Oct 2024 10:06:27 +0800, Joseph Qi wrote:
>>>>> Reported-and-tested-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com
>>>>> Closes: https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
>>>>> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
>>>>> ---
>>>>> V1 -> V2: keep rc to 0 when falgs contains READHEAD
>>>>> V2 -> V3: check i_size only and alert subject and comments
>>>>>
>>>>> fs/ocfs2/extent_map.c | 6 +++++-
>>>>> 1 file changed, 5 insertions(+), 1 deletion(-)
>>>>>
>>>>> #syz test
>>>>>
>>>>> diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
>>>>> index f7672472fa82..29d27a70dbdd 100644
>>>>> --- a/fs/ocfs2/extent_map.c
>>>>> +++ b/fs/ocfs2/extent_map.c
>>>>> @@ -961,13 +961,17 @@ int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
>>>>> int rc = 0;
>>>>> u64 p_block, p_count;
>>>>> int i, count, done = 0;
>>>>> + loff_t i_size = i_size_read(inode);
>>>>>
>>>>> trace_ocfs2_read_virt_blocks(
>>>>> inode, (unsigned long long)v_block, nr, bhs, flags,
>>>>> validate);
>>>>>
>>>>> + if (!i_size)
>>>>> + return -EINVAL;
>>>>> +
>>>>
>>>> Take a more consideration, inode size 0 doesn't mean it has no blocks,
>>>> since we have a case that fallocate with KEEP_SIZE.
>>>> Could you please check inode->i_blocks in above coredump?
>>> I have previously verified the value of inode->i_blocks in my testing environment, which is 0.
>>>
>> So it seems the check condition should be:
>>
>> (v_block + nr) > (inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9))
> Do you mean like this?
>
> diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
> index f7672472fa82..9613cd356ac5 100644
> --- a/fs/ocfs2/extent_map.c
> +++ b/fs/ocfs2/extent_map.c
> @@ -966,6 +966,9 @@ int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
> inode, (unsigned long long)v_block, nr, bhs, flags,
> validate);
>
> + if ((v_block + nr) > (inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9)))
> + return -EINVAL;
> +
> if (((v_block + nr - 1) << inode->i_sb->s_blocksize_bits) >=
> i_size_read(inode)) {
> BUG_ON(!(flags & OCFS2_BH_READAHEAD));
>
Right, which mean the block read request is invalid.
On 10/16/24 10:06 AM, Joseph Qi wrote:
>
>
> On 10/14/24 7:47 PM, Edward Adam Davis wrote:
>> Syzbot reported a BUG in ocfs2_read_virt_blocks.
>> ------------[ cut here ]------------
>> kernel BUG at fs/ocfs2/extent_map.c:971!
>> Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
>> CPU: 1 UID: 0 PID: 5221 Comm: syz-executor117 Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
>> RIP: 0010:ocfs2_read_virt_blocks+0xaa3/0xb20 fs/ocfs2/extent_map.c:971
>> Code: 8b 54 24 30 8b 4c 24 1c 4c 8b 44 24 38 45 89 e1 ff 74 24 48 e8 7e 0a 0c 00 48 83 c4 08 eb 25 e8 43 d2 34 08 e8 ee d1 0c fe 90 <0f> 0b e8 e6 d1 0c fe 4c 89 e8 45 89 e5 49 89 c4 e9 01 f7 ff ff e8
>> RSP: 0018:ffffc90002e2e820 EFLAGS: 00010293
>> RAX: ffffffff83881432 RBX: 0000000000000000 RCX: ffff88802d3e9e00
>> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
>> RBP: ffffc90002e2e9f0 R08: ffffffff83880eae R09: 1ffffffff203781d
>> R10: dffffc0000000000 R11: fffffbfff203781e R12: ffff8880764d8878
>> R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff920005c5d18
>> FS: 000055557cd55380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 00005628fd41e058 CR3: 000000002d2e6000 CR4: 00000000003526f0
>> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>> Call Trace:
>> <TASK>
>> ocfs2_read_dir_block+0x106/0x5c0 fs/ocfs2/dir.c:508
>> ocfs2_find_dir_space_el fs/ocfs2/dir.c:3427 [inline] // status = ocfs2_read_dir_block(dir, 0, &bh, 0);
>
> As I replied before, the comment behind seems unneeded.
>
>> ocfs2_prepare_dir_for_insert+0x3f2/0x5c60 fs/ocfs2/dir.c:4274
>> ocfs2_mknod+0xcaf/0x2b40 fs/ocfs2/namei.c:292
>> ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
>> lookup_open fs/namei.c:3595 [inline]
>> open_last_lookups fs/namei.c:3694 [inline]
>> path_openat+0x1c03/0x3590 fs/namei.c:3930
>> do_filp_open+0x235/0x490 fs/namei.c:3960
>> do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
>> do_sys_open fs/open.c:1430 [inline]
>> __do_sys_openat fs/open.c:1446 [inline]
>> __se_sys_openat fs/open.c:1441 [inline]
>> __x64_sys_openat+0x247/0x2a0 fs/open.c:1441
>> do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>> do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
>> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>
>> In this path, v_block(0), flags(0), and nr(1) are fixed values that are
>> hard coded, so if i_size is 0, the bug will be triggered.
>>
>
> This is not a proper commit log.
> You have to convert to the user scenario, but not simply list the
> parameters value that cause the issue.
>
>> Reported-and-tested-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com
>> Closes: https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
>> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
>> ---
>> V1 -> V2: keep rc to 0 when falgs contains READHEAD
>> V2 -> V3: check i_size only and alert subject and comments
>>
>> fs/ocfs2/extent_map.c | 6 +++++-
>> 1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> #syz test
>>
BTW, please don't mix syzbot test command into the formal patch.
>> diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
>> index f7672472fa82..29d27a70dbdd 100644
>> --- a/fs/ocfs2/extent_map.c
>> +++ b/fs/ocfs2/extent_map.c
>> @@ -961,13 +961,17 @@ int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
>> int rc = 0;
>> u64 p_block, p_count;
>> int i, count, done = 0;
>> + loff_t i_size = i_size_read(inode);
>>
>> trace_ocfs2_read_virt_blocks(
>> inode, (unsigned long long)v_block, nr, bhs, flags,
>> validate);
>>
>> + if (!i_size)
>> + return -EINVAL;
>> +
>
> Take a more consideration, inode size 0 doesn't mean it has no blocks,
> since we have a case that fallocate with KEEP_SIZE.
> Could you please check inode->i_blocks in above coredump?
>
> Thanks,
> Joseph
>
>> if (((v_block + nr - 1) << inode->i_sb->s_blocksize_bits) >=
>> - i_size_read(inode)) {
>> + i_size) {
>> BUG_ON(!(flags & OCFS2_BH_READAHEAD));
>> goto out;
>> }
>
Hello, syzbot has tested the proposed patch and the reproducer did not trigger any issue: Reported-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com Tested-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com Tested on: commit: 6485cf5e Merge tag 'hid-for-linus-2024101301' of git:/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17186887980000 kernel config: https://syzkaller.appspot.com/x/.config?x=164d2822debd8b0d dashboard link: https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 patch: https://syzkaller.appspot.com/x/patch.diff?x=14cb0030580000 Note: testing is done by a robot and is best-effort only.
Let syzbot test this patch first.
(Hope I used the right command to trigger the test.)
----
Syzbot reported a BUG in ocfs2_read_virt_blocks.
------------[ cut here ]------------
kernel BUG at fs/ocfs2/extent_map.c:971!
Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 1 UID: 0 PID: 5221 Comm: syz-executor117 Not tainted 6.12.0-rc2-syzkaller-00006-g87d6aab2389e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:ocfs2_read_virt_blocks+0xaa3/0xb20 fs/ocfs2/extent_map.c:971
Code: 8b 54 24 30 8b 4c 24 1c 4c 8b 44 24 38 45 89 e1 ff 74 24 48 e8 7e 0a 0c 00 48 83 c4 08 eb 25 e8 43 d2 34 08 e8 ee d1 0c fe 90 <0f> 0b e8 e6 d1 0c fe 4c 89 e8 45 89 e5 49 89 c4 e9 01 f7 ff ff e8
RSP: 0018:ffffc90002e2e820 EFLAGS: 00010293
RAX: ffffffff83881432 RBX: 0000000000000000 RCX: ffff88802d3e9e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90002e2e9f0 R08: ffffffff83880eae R09: 1ffffffff203781d
R10: dffffc0000000000 R11: fffffbfff203781e R12: ffff8880764d8878
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff920005c5d18
FS: 000055557cd55380(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005628fd41e058 CR3: 000000002d2e6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
ocfs2_read_dir_block+0x106/0x5c0 fs/ocfs2/dir.c:508
ocfs2_find_dir_space_el fs/ocfs2/dir.c:3427 [inline] // status = ocfs2_read_dir_block(dir, 0, &bh, 0);
ocfs2_prepare_dir_for_insert+0x3f2/0x5c60 fs/ocfs2/dir.c:4274
ocfs2_mknod+0xcaf/0x2b40 fs/ocfs2/namei.c:292
ocfs2_create+0x1ab/0x480 fs/ocfs2/namei.c:672
lookup_open fs/namei.c:3595 [inline]
open_last_lookups fs/namei.c:3694 [inline]
path_openat+0x1c03/0x3590 fs/namei.c:3930
do_filp_open+0x235/0x490 fs/namei.c:3960
do_sys_openat2+0x13e/0x1d0 fs/open.c:1415
do_sys_open fs/open.c:1430 [inline]
__do_sys_openat fs/open.c:1446 [inline]
__se_sys_openat fs/open.c:1441 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1441
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
It is because the parameter v_block passed to ocfs2_read_virt_blocks() is 0,
nr is 1, and inode->i_size is 0, and flags are also 0.
In this path, v_block, flags, and nr are fixed values that are hard coded,
so if i_size is 0, the bug will be triggered.
Therefore, it is more meaningful to check if the flags contain the READHEAD
bit when their value is non-zero.
Reported-and-tested-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
V1 -> V2: keep rc to 0 when falgs contains READHEAD
fs/ocfs2/extent_map.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
#syz test
diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c
index f7672472fa82..0043c2428ef2 100644
--- a/fs/ocfs2/extent_map.c
+++ b/fs/ocfs2/extent_map.c
@@ -968,7 +968,8 @@ int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr,
if (((v_block + nr - 1) << inode->i_sb->s_blocksize_bits) >=
i_size_read(inode)) {
- BUG_ON(!(flags & OCFS2_BH_READAHEAD));
+ BUG_ON(flags && !(flags & OCFS2_BH_READAHEAD));
+ rc = flags ? 0 : -EIO;
goto out;
}
--
2.43.0Hello, syzbot has tested the proposed patch and the reproducer did not trigger any issue: Reported-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com Tested-by: syzbot+797d4829dafe3f11dce7@syzkaller.appspotmail.com Tested on: commit: 6485cf5e Merge tag 'hid-for-linus-2024101301' of git:/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17169440580000 kernel config: https://syzkaller.appspot.com/x/.config?x=164d2822debd8b0d dashboard link: https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7 compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 patch: https://syzkaller.appspot.com/x/patch.diff?x=12e20030580000 Note: testing is done by a robot and is best-effort only.
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