[syzbot] [kernel?] BUG: unable to handle kernel paging request in cirrus_primary_plane_helper_atomic_update

[syzbot] [kernel?] BUG: unable to handle kernel paging request in cirrus_primary_plane_helper_atomic_update

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    3eb40771c00a Merge tag 'soc-fixes-7.2-3' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13949949580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1d67342c314f228d
dashboard link: https://syzkaller.appspot.com/bug?extid=2442951a6abb004df963
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=10d696c6580000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2442951a6abb004df963@syzkaller.appspotmail.com

BUG: unable to handle page fault for address: ffffc900030a7000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 1c000067 P4D 1c000067 PUD 1d6a8067 PMD 25dcb067 PTE 0

Oops: Oops: 0002 [#1] SMP KASAN NOPTI
CPU: 3 UID: 0 PID: 5985 Comm: syz-executor238 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
RIP: 0010:rep_movs arch/x86/lib/iomem.c:13 [inline]
RIP: 0010:string_memcpy_toio arch/x86/lib/iomem.c:64 [inline]
RIP: 0010:memcpy_toio+0x87/0xe0 arch/x86/lib/iomem.c:110
Code: b6 fc 49 89 dd 31 ff 41 83 e5 02 4c 89 ee e8 70 3f b6 fc 4d 85 ed 75 33 e8 c6 44 b6 fc 48 89 e9 48 89 df 4c 89 e6 48 c1 e9 02 <f3> a5 40 f6 c5 02 74 02 66 a5 40 f6 c5 01 74 01 a4 e8 a3 44 b6 fc
RSP: 0018:ffffc900036ef4f0 EFLAGS: 00010206

RAX: 0000000000000000 RBX: ffffc900030a6d20 RCX: 00000000000000d8
RDX: ffff88802dc8a540 RSI: ffffc90003c31f60 RDI: ffffc900030a7000
RBP: 0000000000000640 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc90003c31c80
R13: 0000000000000000 R14: ffffc900030a6d20 R15: 0000000000000640
FS:  0000000000000000(0000) GS:ffff8880d5ede000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc900030a7000 CR3: 000000003cd11000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 iosys_map_memcpy_to include/linux/iosys-map.h:285 [inline]
 drm_fb_memcpy+0x459/0x620 drivers/gpu/drm/drm_format_helper.c:442
 cirrus_primary_plane_helper_atomic_update+0xb1d/0xfe0 drivers/gpu/drm/tiny/cirrus-qemu.c:358
 drm_atomic_helper_commit_planes+0x497/0xf10 drivers/gpu/drm/drm_atomic_helper.c:3038
 drm_atomic_helper_commit_tail+0x7f/0x130 drivers/gpu/drm/drm_atomic_helper.c:1989
 commit_tail+0x338/0x430 drivers/gpu/drm/drm_atomic_helper.c:2074
 drm_atomic_helper_commit+0x303/0x380 drivers/gpu/drm/drm_atomic_helper.c:2312
 drm_atomic_commit+0x230/0x300 drivers/gpu/drm/drm_atomic.c:1789
 drm_client_modeset_commit_atomic+0x6a6/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1104
 drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1207
 drm_client_modeset_commit+0x4f/0x80 drivers/gpu/drm/drm_client_modeset.c:1233
 __drm_fb_helper_restore_fbdev_mode_unlocked.part.0+0x137/0x160 drivers/gpu/drm/drm_fb_helper.c:138
 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:126 [inline]
 drm_fb_helper_restore_fbdev_mode_unlocked+0x93/0xc0 drivers/gpu/drm/drm_fb_helper.c:169
 drm_fbdev_client_restore+0x1b/0x30 drivers/gpu/drm/clients/drm_fbdev_client.c:45
 drm_client_dev_restore+0x205/0x2a0 drivers/gpu/drm/drm_client_event.c:118
 drm_lastclose drivers/gpu/drm/drm_file.c:408 [inline]
 drm_release+0x2c6/0x360 drivers/gpu/drm/drm_file.c:441
 __fput+0x3ff/0xb50 fs/file_table.c:512
 task_work_run+0x150/0x240 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x951/0x2ae0 kernel/exit.c:1009
 do_group_exit+0xd5/0x2a0 kernel/exit.c:1152
 __do_sys_exit_group kernel/exit.c:1163 [inline]
 __se_sys_exit_group kernel/exit.c:1161 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1161
 x64_sys_call+0x102c/0x1530 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6d6a4b3905
Code: Unable to access opcode bytes at 0x7f6d6a4b38db.
RSP: 002b:00007ffd867f5c08 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f6d6a4b3905
RDX: 00000000000000e7 RSI: ffffffffffffffd8 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000001
R13: 00007f6d6a548100 R14: 00007f6d6a54a388 R15: 00007f6d6a54a3a0
 </TASK>
Modules linked in:
CR2: ffffc900030a7000
---[ end trace 0000000000000000 ]---
RIP: 0010:rep_movs arch/x86/lib/iomem.c:13 [inline]
RIP: 0010:string_memcpy_toio arch/x86/lib/iomem.c:64 [inline]
RIP: 0010:memcpy_toio+0x87/0xe0 arch/x86/lib/iomem.c:110
Code: b6 fc 49 89 dd 31 ff 41 83 e5 02 4c 89 ee e8 70 3f b6 fc 4d 85 ed 75 33 e8 c6 44 b6 fc 48 89 e9 48 89 df 4c 89 e6 48 c1 e9 02 <f3> a5 40 f6 c5 02 74 02 66 a5 40 f6 c5 01 74 01 a4 e8 a3 44 b6 fc
RSP: 0018:ffffc900036ef4f0 EFLAGS: 00010206
RAX: 0000000000000000 RBX: ffffc900030a6d20 RCX: 00000000000000d8
RDX: ffff88802dc8a540 RSI: ffffc90003c31f60 RDI: ffffc900030a7000
RBP: 0000000000000640 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc90003c31c80
R13: 0000000000000000 R14: ffffc900030a6d20 R15: 0000000000000640
FS:  0000000000000000(0000) GS:ffff8880d5ede000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffc900030a7000 CR3: 000000003cd11000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	b6 fc                	mov    $0xfc,%dh
   2:	49 89 dd             	mov    %rbx,%r13
   5:	31 ff                	xor    %edi,%edi
   7:	41 83 e5 02          	and    $0x2,%r13d
   b:	4c 89 ee             	mov    %r13,%rsi
   e:	e8 70 3f b6 fc       	call   0xfcb63f83
  13:	4d 85 ed             	test   %r13,%r13
  16:	75 33                	jne    0x4b
  18:	e8 c6 44 b6 fc       	call   0xfcb644e3
  1d:	48 89 e9             	mov    %rbp,%rcx
  20:	48 89 df             	mov    %rbx,%rdi
  23:	4c 89 e6             	mov    %r12,%rsi
  26:	48 c1 e9 02          	shr    $0x2,%rcx
* 2a:	f3 a5                	rep movsl %ds:(%rsi),%es:(%rdi) <-- trapping instruction
  2c:	40 f6 c5 02          	test   $0x2,%bpl
  30:	74 02                	je     0x34
  32:	66 a5                	movsw  %ds:(%rsi),%es:(%rdi)
  34:	40 f6 c5 01          	test   $0x1,%bpl
  38:	74 01                	je     0x3b
  3a:	a4                   	movsb  %ds:(%rsi),%es:(%rdi)
  3b:	e8 a3 44 b6 fc       	call   0xfcb644e3


---
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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.

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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);

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