[syzbot] [usb?] UBSAN: array-index-out-of-bounds in uea_bind

[syzbot] [usb?] UBSAN: array-index-out-of-bounds in uea_bind

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    3708dd948844 Merge tag 'pm-7.2-rc6' of git://git.kernel.or..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14ff71b9580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=145fa60d73086782
dashboard link: https://syzkaller.appspot.com/bug?extid=92f5bf49bf4ac75223ca
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11a0a5b9580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=12ff71b9580000

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-3708dd94.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/57f69e2a6e3b/vmlinux-3708dd94.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3511d4246fb6/bzImage-3708dd94.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+92f5bf49bf4ac75223ca@syzkaller.appspotmail.com

usb 5-1: reset high-speed USB device number 6 using dummy_hcd
usb 5-1: device descriptor read/64, error -71
usb 5-1: reset high-speed USB device number 6 using dummy_hcd
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in drivers/usb/atm/ueagle-atm.c:2466:28
index 4 is out of range for type 'bool [4]'
CPU: 2 UID: 0 PID: 847 Comm: kworker/2:2 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
Workqueue: usb_hub_wq hub_event
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
 uea_bind+0x1014/0x1380 drivers/usb/atm/ueagle-atm.c:2466
 usbatm_usb_probe+0x378/0x1b50 drivers/usb/atm/usbatm.c:1058
 uea_probe+0x194/0x570 drivers/usb/atm/ueagle-atm.c:2597
 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3772
 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268
 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __device_attach_driver+0x1df/0x320 drivers/base/dd.c:1026
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1098
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x64/0x160 drivers/base/bus.c:620
 device_add+0x121d/0x1970 drivers/base/core.c:3772
 usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x30a3/0x4a60 drivers/usb/core/hub.c:5953
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
---[ end trace ]---


---
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 syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

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

Forwarded: [PATCH] usb: Fix UBSAN out-of-bounds

[syzbot]

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

***

Subject: [PATCH] usb: Fix UBSAN out-of-bounds
Author: subasris1210@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git 5d5fd841c34649f1b09220fe58e59dffd61c447d

---
 drivers/usb/atm/ueagle-atm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/atm/ueagle-atm.c b/drivers/usb/atm/ueagle-atm.c
index 4266a0cb7e3b..61723e7ab351 100644
--- a/drivers/usb/atm/ueagle-atm.c
+++ b/drivers/usb/atm/ueagle-atm.c
@@ -2463,7 +2463,8 @@ static int uea_bind(struct usbatm_data *usbatm, struct usb_interface *intf,
 	if (ifnum != UEA_INTR_IFACE_NO)
 		return -ENODEV;
 
-	usbatm->flags = (sync_wait[modem_index] ? 0 : UDSL_SKIP_HEAVY_INIT);
+	usbatm->flags = (modem_index < NB_MODEM && sync_wait[modem_index]) ?
+			 0 : UDSL_SKIP_HEAVY_INIT;
 
 	/* interface 1 is for outbound traffic */
 	ret = claim_interface(usb, usbatm, UEA_US_IFACE_NO);
-- 
2.43.0

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 762137ff748fa0c920f82ce718163691cb02f907

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 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] UBSAN: array-index-out-of-bounds in uea_bind

[syzbot]

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

***

Subject: [PATCH] UBSAN: array-index-out-of-bounds in uea_bind
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

[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

[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+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.

***

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

[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 069f4aad347e1f3181639d2dfbadfae592df93e7

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 069f4aad347e1f3181639d2dfbadfae592df93e7

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 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);
 

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

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

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: 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

[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: 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

[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: 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);

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: alsowereme@outlook.com

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