[syzbot] [raid?] UBSAN: array-index-out-of-bounds in super_90_sync

[syzbot] [raid?] UBSAN: array-index-out-of-bounds in super_90_sync

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    893e11787f78 Merge tag 'x86_urgent_for_7.3-rc3' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11af7af9580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8c5c3949d762a91f
dashboard link: https://syzkaller.appspot.com/bug?extid=9e3014263a35700ab49b
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/7d6d05cecce7/disk-893e1178.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f4fa34852d36/vmlinux-893e1178.xz
kernel image: https://storage.googleapis.com/syzbot-assets/5a45af623528/bzImage-893e1178.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9e3014263a35700ab49b@syzkaller.appspotmail.com

md: async del_gendisk mode will be removed in future, please upgrade to mdadm-4.5+
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in drivers/md/md.c:1697:17
index 124 is out of range for type 'mdp_disk_t [27]'
CPU: 1 UID: 0 PID: 10197 Comm: syz.3.1362 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 ubsan_epilogue+0xa/0x30 lib/ubsan.c:233
 __ubsan_handle_out_of_bounds+0xcc/0xf0 lib/ubsan.c:455
 super_90_sync+0x1eed/0x1ff0 drivers/md/md.c:1697
 sync_super drivers/md/md.c:2505 [inline]
 sync_sbs drivers/md/md.c:2747 [inline]
 md_update_sb+0xbba/0x2840 drivers/md/md.c:2923
 state_store+0x31e/0x1340 drivers/md/md.c:3245
 rdev_attr_store+0x465/0x560 drivers/md/md.c:3768
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6af/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f977e59e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f977f3cb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f977e825fa0 RCX: 00007f977e59e159
RDX: 000000000000000b RSI: 0000200000000a00 RDI: 0000000000000006
RBP: 00007f977e63503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f977e826038 R14: 00007f977e825fa0 R15: 00007ffef91f5d68
 </TASK>
---[ end trace ]---


---
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If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
#syz undup

Re: [syzbot] [raid?] UBSAN: array-index-out-of-bounds in super_90_sync

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    2f0c1cf72f46 Merge tag 's390-7.3-3' of git://git.kernel.or..
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=14afd5f9580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8c5c3949d762a91f
dashboard link: https://syzkaller.appspot.com/bug?extid=9e3014263a35700ab49b
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12afd5f9580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9e3014263a35700ab49b@syzkaller.appspotmail.com

------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in drivers/md/md.c:1697:17
index 124 is out of range for type 'mdp_disk_t [27]'
CPU: 1 UID: 0 PID: 6018 Comm: syz-executor186 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 ubsan_epilogue+0xa/0x30 lib/ubsan.c:233
 __ubsan_handle_out_of_bounds+0xcc/0xf0 lib/ubsan.c:455
 super_90_sync+0x1eed/0x1ff0 drivers/md/md.c:1697
 sync_super drivers/md/md.c:2505 [inline]
 sync_sbs drivers/md/md.c:2747 [inline]
 md_update_sb+0xbba/0x2840 drivers/md/md.c:2923
 state_store+0x31e/0x1340 drivers/md/md.c:3245
 rdev_attr_store+0x1d9/0x560 drivers/md/md.c:3768
 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145
 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x6af/0x1050 fs/read_write.c:687
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f84634ad6f7
Code: 48 89 fa 4c 89 df e8 98 1d 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fff04c70ef0 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00005555934c5400 RCX: 00007f84634ad6f7
RDX: 0000000000000008 RSI: 00007f84634e9c12 RDI: 0000000000000003
RBP: 00007f84634e9c12 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff04c70fc0
R13: 00007f84634e9b5f R14: 00007fff04c710d0 R15: 0000000000000002
 </TASK>
---[ end trace ]---


---
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.

Forwarded: [PATCH] md: validate raid_disks against MD_SB_DISKS in super_90_load

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: [PATCH] md: validate raid_disks against MD_SB_DISKS in super_90_load
Author: kartikey406@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master


The v0.90 superblock format can only describe MD_SB_DISKS (27) member
disks, but super_90_load() only checks that sb->raid_disks is
positive, not that it fits within this limit.

A crafted/corrupt superblock with an oversized raid_disks value is
accepted and copied into mddev->raid_disks. When the superblock is
later rewritten (e.g. via a write to the rdev 'state' sysfs
attribute), super_90_sync() uses this value to index sb->disks[],
causing an out-of-bounds array access:

  UBSAN: array-index-out-of-bounds in drivers/md/md.c:1697:17
  index 124 is out of range for type 'mdp_disk_t [27]'

Reject superblocks whose raid_disks value cannot be represented by
the v0.90 format at load time, before it is trusted anywhere else.

Reported-by: syzbot+9e3014263a35700ab49b@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9e3014263a35700ab49b
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
---
 drivers/md/md.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 680b34a63cb3..c65da77677bc 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1393,7 +1393,8 @@ static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor
 		goto abort;
 	}
 
-	if (sb->raid_disks <= 0)
+	if (sb->raid_disks <= 0 ||
+            sb->raid_disks > MD_SB_DISKS)
 		goto abort;
 
 	if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
-- 
2.34.1

Forwarded: [PATCH] md: fix out-of-bounds access to superblock disk array

[syzbot]

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linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

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Subject: [PATCH] md: fix out-of-bounds access to superblock disk array
Author: kartikey406@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master



The v0.90 superblock format can only describe MD_SB_DISKS (27) member
disks, but several places did not enforce this limit, allowing an
out-of-bounds access to sb->disks[]:

 1. super_90_load() only checked that sb->raid_disks was positive,
    not that it fit within MD_SB_DISKS. A crafted superblock with an
    oversized raid_disks value was accepted into mddev->raid_disks.

 2. super_90_sync() computed desc_nr from rdev2->raid_disk or a
    running spare counter without checking it stayed within bounds
    before indexing sb->disks[desc_nr].

 3. super_90_sync() also indexed sb->disks[rdev->desc_nr] for
    sb->this_disk without any bounds check.

 4. The "missing devices" loop in super_90_sync() iterated up to
    mddev->raid_disks with no per-iteration bound on sb->disks[].

Any of these could be reached with a bad raid_disks/desc_nr value
and cause an out-of-bounds array access:

  UBSAN: array-index-out-of-bounds in drivers/md/md.c:1697:17
  index 124 is out of range for type 'mdp_disk_t [27]'

Validate raid_disks at load time, and add bounds checks at each
point sb->disks[] is indexed as defense in depth.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot+9e3014263a35700ab49b@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9e3014263a35700ab49b
Assisted-by: Claude
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
---
 drivers/md/md.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 680b34a63cb3..f950e6fd144c 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1393,7 +1393,8 @@ static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor
 		goto abort;
 	}
 
-	if (sb->raid_disks <= 0)
+	if (sb->raid_disks <= 0 ||
+            sb->raid_disks > MD_SB_DISKS)
 		goto abort;
 
 	if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
@@ -1693,6 +1694,13 @@ static void super_90_sync(struct mddev *mddev, struct md_rdev *rdev)
 			desc_nr = rdev2->raid_disk;
 		else
 			desc_nr = next_spare++;
+
+		if (desc_nr < 0 || desc_nr >= MD_SB_DISKS) {
+			pr_warn("md: %s: desc_nr %d out of range for rdev %pg, skipping\n",
+			        mdname(mddev), desc_nr, rdev2->bdev);
+			continue;
+		}
+
 		rdev2->desc_nr = desc_nr;
 		d = &sb->disks[rdev2->desc_nr];
 		nr_disks++;
@@ -1722,7 +1730,7 @@ static void super_90_sync(struct mddev *mddev, struct md_rdev *rdev)
 			d->state |= (1<<MD_DISK_FAILFAST);
 	}
 	/* now set the "removed" and "faulty" bits on any missing devices */
-	for (i=0 ; i < mddev->raid_disks ; i++) {
+	for (i=0 ; i < mddev->raid_disks && i < MD_SB_DISKS ; i++) {
 		mdp_disk_t *d = &sb->disks[i];
 		if (d->state == 0 && d->number == 0) {
 			d->number = i;
@@ -1737,8 +1745,11 @@ static void super_90_sync(struct mddev *mddev, struct md_rdev *rdev)
 	sb->working_disks = working;
 	sb->failed_disks = failed;
 	sb->spare_disks = spare;
-
-	sb->this_disk = sb->disks[rdev->desc_nr];
+	if (rdev->desc_nr >= 0 && rdev->desc_nr < MD_SB_DISKS)
+		sb->this_disk = sb->disks[rdev->desc_nr];
+	else
+		pr_warn("md: %s: rdev desc_nr %d out of range, this_disk not set\n",
+			mdname(mddev), rdev->desc_nr);
 	sb->sb_csum = calc_sb_csum(sb);
 }
 
-- 
2.34.1

Forwarded: [PATCH] configfs: unhash dentry before dropping the item

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

***

Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: jchuang26@m.fudan.edu.cn

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

Reported-by: syzbot+9e3014263a35700ab49b@syzkaller.appspotmail.com

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 680b34a63..bcc32b83c 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1393,7 +1393,11 @@ static int super_90_load(struct md_rdev *rdev, struct md_rdev *refdev, int minor
 		goto abort;
 	}
 
-	if (sb->raid_disks <= 0)
+	/*
+	 * sb->disks[] has only MD_SB_DISKS entries.  A larger raid_disks
+	 * count would later make super_90_sync() index past that array.
+	 */
+	if (sb->raid_disks <= 0 || sb->raid_disks > MD_SB_DISKS)
 		goto abort;
 
 	if (md_csum_fold(calc_sb_csum(sb)) != md_csum_fold(sb->sb_csum)) {
@@ -1607,6 +1611,18 @@ static void super_90_sync(struct mddev *mddev, struct md_rdev *rdev)
 	struct md_rdev *rdev2;
 	int next_spare = mddev->raid_disks;
 
+	/*
+	 * A 0.90 superblock has a fixed-size mdp_disk_t array and uses
+	 * raid_disks as both a loop bound and the first spare disk slot.
+	 * Never index sb->disks[] if an invalid raid_disks value reached
+	 * us through any configuration path.
+	 */
+	if (mddev->raid_disks < 0 || mddev->raid_disks > MD_SB_DISKS) {
+		pr_warn("md: %s: invalid raid_disks %d for 0.90 metadata\n",
+			mdname(mddev), mddev->raid_disks);
+		return;
+	}
+
 	/* make rdev->sb match mddev data..
 	 *
 	 * 1/ zero out disks
@@ -4448,8 +4464,19 @@ raid_disks_store(struct mddev *mddev, const char *buf, size_t len)
 		mddev->delta_disks = n - olddisks;
 		mddev->raid_disks = n;
 		mddev->reshape_backwards = (mddev->delta_disks < 0);
-	} else
-		mddev->raid_disks = n;
+	} else {
+		/*
+		 * 0.90 metadata only has room for MD_SB_DISKS descriptors.
+		 * Larger values would make super_90_sync() index beyond
+		 * sb->disks[].
+		 */
+		if ((mddev->persistent && mddev->major_version == 0 &&
+		     n > MD_SB_DISKS) ||
+		    (mddev->max_disks && n > mddev->max_disks))
+			err = -EINVAL;
+		else
+			mddev->raid_disks = n;
+	}
 out_unlock:
 	memalloc_noio_restore(noio_flags);
 	mddev_unlock_and_resume(mddev);
@@ -7926,6 +7953,18 @@ int md_set_array_info(struct mddev *mddev, struct mdu_array_info_s *info)
 		mddev->ctime         = ktime_get_real_seconds();
 		return 0;
 	}
+
+	/*
+	 * Persistent 0.90 metadata stores disks in sb->disks[MD_SB_DISKS].
+	 * A larger raid_disks count would make super_90_sync() index past
+	 * that array; non-persistent arrays have no such on-disk limit.
+	 */
+	if (info->raid_disks < 0 ||
+	    (!info->not_persistent && info->raid_disks > MD_SB_DISKS)) {
+		pr_warn("md: invalid raid_disks %d\n", info->raid_disks);
+		return -EINVAL;
+	}
+
 	mddev->major_version = MD_MAJOR_VERSION;
 	mddev->minor_version = MD_MINOR_VERSION;
 	mddev->patch_version = MD_PATCHLEVEL_VERSION;

Forwarded: [PATCH] configfs: unhash dentry before dropping the item

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linux-kernel@vger.kernel.org.

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Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: jchuang26@m.fudan.edu.cn

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

Reported-by: syzbot+a079f084653164a652d1@syzkaller.appspotmail.com

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 53fbdbbe8..3c5f7c80b 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -1410,9 +1410,12 @@ batadv_iv_ogm_update_seqnos(const struct ethhdr *ethhdr,
 		return BATADV_NO_DUP;
 
 	orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
-	if (WARN_ON(!orig_ifinfo)) {
+	/* batadv_orig_ifinfo_new() can fail when the memory allocation fails.
+	 * This is not a bug, so don't warn and treat the OGM as non-duplicate.
+	 */
+	if (!orig_ifinfo) {
 		batadv_orig_node_put(orig_node);
-		return 0;
+		return BATADV_NO_DUP;
 	}
 
 	spin_lock_bh(&orig_node->bat_iv.ogm_cnt_lock);

Forwarded: [PATCH] configfs: unhash dentry before dropping the item

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org.

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Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: jchuang26@m.fudan.edu.cn

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 50d05c7c76c96b90462f24debacca971d2e86713

Reported-by: syzbot+a079f084653164a652d1@syzkaller.appspotmail.com

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 53fbdbbe8..3c5f7c80b 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -1410,9 +1410,12 @@ batadv_iv_ogm_update_seqnos(const struct ethhdr *ethhdr,
 		return BATADV_NO_DUP;
 
 	orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
-	if (WARN_ON(!orig_ifinfo)) {
+	/* batadv_orig_ifinfo_new() can fail when the memory allocation fails.
+	 * This is not a bug, so don't warn and treat the OGM as non-duplicate.
+	 */
+	if (!orig_ifinfo) {
 		batadv_orig_node_put(orig_node);
-		return 0;
+		return BATADV_NO_DUP;
 	}
 
 	spin_lock_bh(&orig_node->bat_iv.ogm_cnt_lock);

Forwarded: [PATCH] configfs: unhash dentry before dropping the item

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linux-kernel@vger.kernel.org.

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Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: jchuang26@m.fudan.edu.cn

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 762137ff748fa0c920f82ce718163691cb02f907

Reported-by: syzbot+92f5bf49bf4ac75223ca@syzkaller.appspotmail.com

diff --git a/drivers/usb/atm/ueagle-atm.c b/drivers/usb/atm/ueagle-atm.c
index 4266a0cb7..b1b358b3a 100644
--- a/drivers/usb/atm/ueagle-atm.c
+++ b/drivers/usb/atm/ueagle-atm.c
@@ -2458,12 +2458,21 @@ static int uea_bind(struct usbatm_data *usbatm, struct usb_interface *intf,
 	struct uea_softc *sc;
 	int ret, ifnum = intf->altsetting->desc.bInterfaceNumber;
 	unsigned int alt;
+	int modem_idx;
 
 	/* interface 0 is for firmware/monitoring */
 	if (ifnum != UEA_INTR_IFACE_NO)
 		return -ENODEV;
 
-	usbatm->flags = (sync_wait[modem_index] ? 0 : UDSL_SKIP_HEAVY_INIT);
+	/*
+	 * modem_index is a global counter that stops at NB_MODEM once that
+	 * many devices have been probed. Wrap the index the same way as
+	 * sc->modem_index below so that the module parameter lookup stays
+	 * within the bounds of the arrays.
+	 */
+	modem_idx = (modem_index < NB_MODEM) ? modem_index : 0;
+
+	usbatm->flags = (sync_wait[modem_idx] ? 0 : UDSL_SKIP_HEAVY_INIT);
 
 	/* interface 1 is for outbound traffic */
 	ret = claim_interface(usb, usbatm, UEA_US_IFACE_NO);

Forwarded: [PATCH] configfs: unhash dentry before dropping the item

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linux-kernel@vger.kernel.org.

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Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: jchuang26@m.fudan.edu.cn

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 762137ff748fa0c920f82ce718163691cb02f907

Forwarded: [PATCH] configfs: unhash dentry before dropping the item

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Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: jchuang26@m.fudan.edu.cn

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 069f4aad347e1f3181639d2dfbadfae592df93e7

Forwarded: [PATCH] configfs: unhash dentry before dropping the item

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Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: jchuang26@m.fudan.edu.cn

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 069f4aad347e1f3181639d2dfbadfae592df93e7

Forwarded: [PATCH] configfs: unhash dentry before dropping the item

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Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: jchuang26@m.fudan.edu.cn

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 069f4aad347e1f3181639d2dfbadfae592df93e7

Reported-by: syzbot+abd6a8dca0f2b7726060@syzkaller.appspotmail.com

diff --git a/drivers/block/null_blk/zoned.c b/drivers/block/null_blk/zoned.c
index 384bdce6a..1c3ef902f 100644
--- a/drivers/block/null_blk/zoned.c
+++ b/drivers/block/null_blk/zoned.c
@@ -88,6 +88,11 @@ int null_init_zoned_dev(struct nullb_device *dev,
 	zone_capacity_sects = mb_to_sects(dev->zone_capacity);
 	dev_capacity_sects = mb_to_sects(dev->size);
 	dev->zone_size_sects = mb_to_sects(dev->zone_size);
+	if (!dev->zone_size_sects) {
+		pr_err("zone_size is too large\n");
+		return -EINVAL;
+	}
+
 	dev->nr_zones = round_up(dev_capacity_sects, dev->zone_size_sects)
 		>> ilog2(dev->zone_size_sects);
 

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Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: jchuang26@m.fudan.edu.cn

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git a7c1290eef60711c10289c056ad32ed1f2b47b12

Forwarded: [PATCH] configfs: unhash dentry before dropping the item

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Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: jchuang26@m.fudan.edu.cn

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 958f35cbb8955ca3fa439cd9f2092cb42414aa8c

Forwarded: [PATCH] configfs: unhash dentry before dropping the item

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Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: jchuang26@m.fudan.edu.cn

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 958f35cbb8955ca3fa439cd9f2092cb42414aa8c

Reported-by: syzbot+2442951a6abb004df963@syzkaller.appspotmail.com

diff --git a/drivers/gpu/drm/tiny/cirrus-qemu.c b/drivers/gpu/drm/tiny/cirrus-qemu.c
index 075221b43..f66e33f18 100644
--- a/drivers/gpu/drm/tiny/cirrus-qemu.c
+++ b/drivers/gpu/drm/tiny/cirrus-qemu.c
@@ -68,6 +68,7 @@ struct cirrus_device {
 
 	/* HW resources */
 	void __iomem		       *vram;
+	resource_size_t		       vram_size;
 	void __iomem		       *mmio;
 };
 
@@ -298,6 +299,7 @@ static const uint64_t cirrus_primary_plane_format_modifiers[] = {
 static int cirrus_primary_plane_helper_atomic_check(struct drm_plane *plane,
 						    struct drm_atomic_commit *state)
 {
+	struct cirrus_device *cirrus = to_cirrus(plane->dev);
 	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
 	struct drm_framebuffer *fb = new_plane_state->fb;
 	struct drm_crtc *new_crtc = new_plane_state->crtc;
@@ -319,7 +321,7 @@ static int cirrus_primary_plane_helper_atomic_check(struct drm_plane *plane,
 	/* validate size constraints */
 	if (fb->pitches[0] > CIRRUS_MAX_PITCH)
 		return -EINVAL;
-	else if (fb->pitches[0] > CIRRUS_VRAM_SIZE / fb->height)
+	else if (fb->pitches[0] > cirrus->vram_size / fb->height)
 		return -EINVAL;
 
 	return 0;
@@ -514,6 +516,7 @@ static int cirrus_pipe_init(struct cirrus_device *cirrus)
 static enum drm_mode_status cirrus_mode_config_mode_valid(struct drm_device *dev,
 							  const struct drm_display_mode *mode)
 {
+	struct cirrus_device *cirrus = to_cirrus(dev);
 	const struct drm_format_info *format = drm_format_info(DRM_FORMAT_XRGB8888);
 	u64 pitch;
 
@@ -525,7 +528,7 @@ static enum drm_mode_status cirrus_mode_config_mode_valid(struct drm_device *dev
 		return MODE_BAD_WIDTH;
 	if (pitch > CIRRUS_MAX_PITCH)
 		return MODE_BAD_WIDTH; /* maximum programmable pitch */
-	if (pitch > CIRRUS_VRAM_SIZE / mode->vdisplay)
+	if (pitch > cirrus->vram_size / mode->vdisplay)
 		return MODE_MEM;
 
 	return MODE_OK;
@@ -602,8 +605,10 @@ static int cirrus_pci_probe(struct pci_dev *pdev,
 
 	dev = &cirrus->dev;
 
+	cirrus->vram_size = min_t(resource_size_t, pci_resource_len(pdev, 0),
+				 CIRRUS_VRAM_SIZE);
 	cirrus->vram = devm_ioremap(&pdev->dev, pci_resource_start(pdev, 0),
-				    pci_resource_len(pdev, 0));
+				    cirrus->vram_size);
 	if (cirrus->vram == NULL)
 		return -ENOMEM;
 

Forwarded: [PATCH] configfs: unhash dentry before dropping the item

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Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: jchuang26@m.fudan.edu.cn

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git a7c1290eef60711c10289c056ad32ed1f2b47b12

Reported-by: syzbot+6b16e3d085833cbf3e25@syzkaller.appspotmail.com

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 3c88f13f1..d9c222ff0 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -418,6 +418,16 @@ static void configfs_remove_dir(struct dentry *d)
 			pr_warn("remove_dir (%pd): attributes remain", d);
 	}
 
+	/*
+	 * The dentry can still have external references (e.g. from a
+	 * concurrent configfs_symlink() path lookup), in which case
+	 * simple_rmdir() will not have unhashed it yet.  Make sure the
+	 * dentry is unreachable before the caller drops the last
+	 * reference to the config_item, since configfs_symlink() resolves
+	 * targets by taking a reference through a hashed dentry.
+	 */
+	d_drop(d);
+
 	pr_debug(" o %pd removing done (%d)\n", d, d_count(d));
 
 	dput(parent);

Forwarded: [PATCH] configfs: unhash dentry before dropping the item

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Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: jchuang26@m.fudan.edu.cn

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git a7c1290eef60711c10289c056ad32ed1f2b47b12

Reported-by: syzbot+6b16e3d085833cbf3e25@syzkaller.appspotmail.com

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 3c88f13f1..b0812432f 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -1552,12 +1552,14 @@ static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
 
 	if (sd->s_type & CONFIGFS_USET_DIR) {
 		configfs_detach_group(dentry);
+		d_drop(dentry);
 
 		mutex_lock(&subsys->su_mutex);
 		client_disconnect_notify(parent_item, item);
 		unlink_group(to_config_group(item));
 	} else {
 		configfs_detach_item(dentry);
+		d_drop(dentry);
 
 		mutex_lock(&subsys->su_mutex);
 		client_disconnect_notify(parent_item, item);

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Subject: [PATCH] configfs: unhash dentry before dropping the item
Author: alsowereme@outlook.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git a7c1290eef60711c10289c056ad32ed1f2b47b12