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kernel BUG in ocfs2_read_virt_blocks

syzbot Superseded syzbot 4 participants 16 messages Oct 12, 2024 – Oct 16, 2024 OCFS2

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author syzbot
#0 lore raw

Hello,

syzbot found the following issue on:

HEAD commit:    87d6aab2389e Merge tag 'for_linus' of git://git.kernel.org..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=17fbbb80580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7a3fccdd0bb995
dashboard link: https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13c117d0580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1007bb80580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/47c26a185f6d/disk-87d6aab2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fe82dfdaaac4/vmlinux-87d6aab2.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ecaba119a5f0/bzImage-87d6aab2.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/197dcbc41fea/mount_0.gz

Bisection is inconclusive: the issue happens on the oldest tested release.

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=114db707980000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=134db707980000
console output: https://syzkaller.appspot.com/x/log.txt?x=154db707980000

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by [email protected]

JBD2: Ignoring recovery information on journal
ocfs2: Mounting device (7,0) on (node local, slot 0) with ordered data mode.

------------[ 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]
 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
RIP: 0033:0x7fa356467d59
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe912bab08 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa356467d59
RDX: 000000000000275a RSI: 0000000020000040 RDI: 00000000ffffff9c
RBP: 00007fa3564e05f0 R08: 0000000000004472 R09: 000055557cd564c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe912bab30
R13: 00007ffe912bad58 R14: 431bde82d7b634db R15: 00007fa3564b103b
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
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

---
This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at [email protected].

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

#1 lore raw

if the value of flags is 0, it is meaningless to check it contains OCFS2_BH_READAHEAD

#syz test

fs/ocfs2/extent_map.c +2 -1
index f7672472fa82..0043c2428ef2 100644
@@ -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 ?: -EIO;
 		goto out;
 	}
author syzbot Tested-by
#2 lore raw
syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by [email protected]
Tested-by [email protected]

Tested on:

commit:         36c25451 Merge tag 'powerpc-6.12-4' of git://git.kerne..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12860727980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7a3fccdd0bb995
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=17c3f05f980000

Note: testing is done by a robot and is best-effort only.

#3 lore raw

PATCH 1/1 ocfs2: BUG is meaningless when the flags is 0

In reply to syzbot

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 [email protected]
Closes https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by Edward Adam Davis <[email protected]>
---
 fs/ocfs2/extent_map.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
fs/ocfs2/extent_map.c +2 -1
index f7672472fa82..0043c2428ef2 100644
@@ -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 ?: -EIO;
 		goto out;
 	}
Signature · 1 line
2.43.0
#4 lore raw

PATCH v2 1/1 ocfs2: BUG is meaningless when the flags is 0

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 [email protected]
Closes https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by Edward Adam Davis <[email protected]>

---
V1 -> V2: keep rc to 0 when falgs contains READHEAD

 fs/ocfs2/extent_map.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
fs/ocfs2/extent_map.c +2 -1
index f7672472fa82..0043c2428ef2 100644
@@ -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;
 	}
Signature · 1 line
2.43.0
reviewer
#5 lore raw

PATCH v2 1/1 ocfs2: BUG is meaningless when the flags is 0

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 [email protected]
Closes https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by Edward Adam Davis <[email protected]>

---
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

fs/ocfs2/extent_map.c +2 -1
index f7672472fa82..0043c2428ef2 100644
@@ -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;
 	}
Signature · 1 line
2.43.0
author syzbot Tested-by on v2 1/1
#6 lore raw
syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by [email protected]
Tested-by [email protected]

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.

maintainer
#7 lore raw

Re: [PATCH V2] ocfs2: BUG is meaningless when the flags is 0

In reply to Edward Adam Davis
Quoted 15 lines · Edward Adam Davis

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
Quoted 8 lines
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.

Quoted 37 lines
 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 [email protected]
Closes https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by Edward Adam Davis <[email protected]>

---
V1 -> V2: keep rc to 0 when falgs contains READHEAD

 fs/ocfs2/extent_map.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
fs/ocfs2/extent_map.c +0 -0
index f7672472fa82..0043c2428ef2 100644

fs/ocfs2/extent_map.c int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr, · line 971

Quoted 5 lines
fs/ocfs2/extent_map.c +1 -1
@@ -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

Quoted 4 lines
fs/ocfs2/extent_map.c +1 -0
+		rc = flags ? 0 : -EIO;
 		goto out;
 	}
#8 lore raw

PATCH v3 1/1 ocfs2: add a sanity check for i_size

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 [email protected]
Closes https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by Edward Adam Davis <[email protected]>

---
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

fs/ocfs2/extent_map.c +5 -1
index f7672472fa82..29d27a70dbdd 100644
@@ -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;
 	}
Signature · 1 line
2.43.0
author syzbot Tested-by on v3 1/1
#9 lore raw
syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-by [email protected]
Tested-by [email protected]

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.

maintainer
#10 lore raw

Re: [PATCH V3] ocfs2: add a sanity check for i_size

In reply to Edward Adam Davis
Quoted 15 lines · Edward Adam Davis

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
Quoted 8 lines
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.

Quoted 16 lines
 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
Quoted 3 lines

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.

Quoted 19 lines
Reported-and-tested-by [email protected]
Closes https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by Edward Adam Davis <[email protected]>

---
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

fs/ocfs2/extent_map.c +0 -0
index f7672472fa82..29d27a70dbdd 100644
@@ -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;

fs/ocfs2/extent_map.c int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr, · line 972

Quoted 10 lines
fs/ocfs2/extent_map.c +4 -0
 	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

Quoted 6 lines
fs/ocfs2/extent_map.c +1 -1
 	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;
 	}
maintainer
#11 lore raw

Re: [PATCH V3] ocfs2: add a sanity check for i_size

Quoted 45 lines · Joseph Qi
Quoted 15 lines · Edward Adam Davis

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
Quoted 8 lines
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.

Quoted 16 lines
 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
Quoted 20 lines
Quoted 3 lines

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.

Quoted 12 lines
Reported-and-tested-by [email protected]
Closes https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by Edward Adam Davis <[email protected]>

---
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.

Quoted 32 lines
Quoted 7 lines
fs/ocfs2/extent_map.c +0 -0
index f7672472fa82..29d27a70dbdd 100644
@@ -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;

fs/ocfs2/extent_map.c int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr, · line 972

Quoted 10 lines
fs/ocfs2/extent_map.c +4 -0
 	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

Quoted 6 lines
fs/ocfs2/extent_map.c +1 -1
 	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;
 	}
#12 lore raw

Re: [PATCH V3] ocfs2: add a sanity check for i_size

In reply to Joseph Qi
Quoted 26 lines · Joseph Qi
Quoted 26 lines
Reported-and-tested-by [email protected]
Closes https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by Edward Adam Davis <[email protected]>

---
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

fs/ocfs2/extent_map.c +1 -0
index f7672472fa82..29d27a70dbdd 100644
@@ -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);
Quoted 7 lines

fs/ocfs2/extent_map.c int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr, · line 972

Quoted 3 lines
fs/ocfs2/extent_map.c +3 -0
+	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

maintainer
#13 lore raw

Re: [PATCH V3] ocfs2: add a sanity check for i_size

Quoted 27 lines · Edward Adam Davis
Quoted 26 lines · Joseph Qi
Quoted 26 lines
Reported-and-tested-by [email protected]
Closes https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by Edward Adam Davis <[email protected]>

---
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

fs/ocfs2/extent_map.c +1 -0
index f7672472fa82..29d27a70dbdd 100644
@@ -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);
Quoted 9 lines
Quoted 7 lines

fs/ocfs2/extent_map.c int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr, · line 972

Quoted 3 lines
fs/ocfs2/extent_map.c +3 -0
+	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))

#14 lore raw

Re: [PATCH V3] ocfs2: add a sanity check for i_size

Quoted 35 lines · Joseph Qi
Quoted 34 lines · Edward Adam Davis
Quoted 33 lines · Joseph Qi
Quoted 19 lines
Reported-and-tested-by [email protected]
Closes https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by Edward Adam Davis <[email protected]>

---
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

fs/ocfs2/extent_map.c +0 -0
index f7672472fa82..29d27a70dbdd 100644
@@ -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;

fs/ocfs2/extent_map.c int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr, · line 972

Quoted 10 lines
fs/ocfs2/extent_map.c +4 -0
 	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?

Quoted 5 lines
Quoted 2 lines

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?

fs/ocfs2/extent_map.c +3 -0
index f7672472fa82..9613cd356ac5 100644
@@ -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

maintainer
#15 lore raw

Re: [PATCH V3] ocfs2: add a sanity check for i_size

Quoted 49 lines · Edward Adam Davis
Quoted 35 lines · Joseph Qi
Quoted 34 lines · Edward Adam Davis
Quoted 33 lines · Joseph Qi
Quoted 19 lines
Reported-and-tested-by [email protected]
Closes https://syzkaller.appspot.com/bug?extid=797d4829dafe3f11dce7
Signed-off-by Edward Adam Davis <[email protected]>

---
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

fs/ocfs2/extent_map.c +0 -0
index f7672472fa82..29d27a70dbdd 100644
@@ -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;

fs/ocfs2/extent_map.c int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr, · line 972

Quoted 10 lines
fs/ocfs2/extent_map.c +4 -0
 	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?

Quoted 5 lines
Quoted 2 lines

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?

fs/ocfs2/extent_map.c +0 -0
index f7672472fa82..9613cd356ac5 100644

fs/ocfs2/extent_map.c int ocfs2_read_virt_blocks(struct inode *inode, u64 v_block, int nr, · line 974

Quoted 9 lines
fs/ocfs2/extent_map.c +3 -0
@@ -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.