--- /dev/null
+From 01e03fb7db419d39e18d6090d4873c1bff103914 Mon Sep 17 00:00:00 2001
+From: Duoming Zhou <duoming@zju.edu.cn>
+Date: Wed, 17 Sep 2025 17:59:26 +0800
+Subject: media: b2c2: Fix use-after-free causing by irq_check_work in flexcop_pci_remove
+
+From: Duoming Zhou <duoming@zju.edu.cn>
+
+commit 01e03fb7db419d39e18d6090d4873c1bff103914 upstream.
+
+The original code uses cancel_delayed_work() in flexcop_pci_remove(), which
+does not guarantee that the delayed work item irq_check_work has fully
+completed if it was already running. This leads to use-after-free scenarios
+where flexcop_pci_remove() may free the flexcop_device while irq_check_work
+is still active and attempts to dereference the device.
+
+A typical race condition is illustrated below:
+
+CPU 0 (remove) | CPU 1 (delayed work callback)
+flexcop_pci_remove() | flexcop_pci_irq_check_work()
+ cancel_delayed_work() |
+ flexcop_device_kfree(fc_pci->fc_dev) |
+ | fc = fc_pci->fc_dev; // UAF
+
+This is confirmed by a KASAN report:
+
+==================================================================
+BUG: KASAN: slab-use-after-free in __run_timer_base.part.0+0x7d7/0x8c0
+Write of size 8 at addr ffff8880093aa8c8 by task bash/135
+...
+Call Trace:
+ <IRQ>
+ dump_stack_lvl+0x55/0x70
+ print_report+0xcf/0x610
+ ? __run_timer_base.part.0+0x7d7/0x8c0
+ kasan_report+0xb8/0xf0
+ ? __run_timer_base.part.0+0x7d7/0x8c0
+ __run_timer_base.part.0+0x7d7/0x8c0
+ ? __pfx___run_timer_base.part.0+0x10/0x10
+ ? __pfx_read_tsc+0x10/0x10
+ ? ktime_get+0x60/0x140
+ ? lapic_next_event+0x11/0x20
+ ? clockevents_program_event+0x1d4/0x2a0
+ run_timer_softirq+0xd1/0x190
+ handle_softirqs+0x16a/0x550
+ irq_exit_rcu+0xaf/0xe0
+ sysvec_apic_timer_interrupt+0x70/0x80
+ </IRQ>
+...
+
+Allocated by task 1:
+ kasan_save_stack+0x24/0x50
+ kasan_save_track+0x14/0x30
+ __kasan_kmalloc+0x7f/0x90
+ __kmalloc_noprof+0x1be/0x460
+ flexcop_device_kmalloc+0x54/0xe0
+ flexcop_pci_probe+0x1f/0x9d0
+ local_pci_probe+0xdc/0x190
+ pci_device_probe+0x2fe/0x470
+ really_probe+0x1ca/0x5c0
+ __driver_probe_device+0x248/0x310
+ driver_probe_device+0x44/0x120
+ __driver_attach+0xd2/0x310
+ bus_for_each_dev+0xed/0x170
+ bus_add_driver+0x208/0x500
+ driver_register+0x132/0x460
+ do_one_initcall+0x89/0x300
+ kernel_init_freeable+0x40d/0x720
+ kernel_init+0x1a/0x150
+ ret_from_fork+0x10c/0x1a0
+ ret_from_fork_asm+0x1a/0x30
+
+Freed by task 135:
+ kasan_save_stack+0x24/0x50
+ kasan_save_track+0x14/0x30
+ kasan_save_free_info+0x3a/0x60
+ __kasan_slab_free+0x3f/0x50
+ kfree+0x137/0x370
+ flexcop_device_kfree+0x32/0x50
+ pci_device_remove+0xa6/0x1d0
+ device_release_driver_internal+0xf8/0x210
+ pci_stop_bus_device+0x105/0x150
+ pci_stop_and_remove_bus_device_locked+0x15/0x30
+ remove_store+0xcc/0xe0
+ kernfs_fop_write_iter+0x2c3/0x440
+ vfs_write+0x871/0xd70
+ ksys_write+0xee/0x1c0
+ do_syscall_64+0xac/0x280
+ entry_SYSCALL_64_after_hwframe+0x77/0x7f
+...
+
+Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
+that the delayed work item is properly canceled and any executing delayed
+work has finished before the device memory is deallocated.
+
+This bug was initially identified through static analysis. To reproduce
+and test it, I simulated the B2C2 FlexCop PCI device in QEMU and introduced
+artificial delays within the flexcop_pci_irq_check_work() function to
+increase the likelihood of triggering the bug.
+
+Fixes: 382c5546d618 ("V4L/DVB (10694): [PATCH] software IRQ watchdog for Flexcop B2C2 DVB PCI cards")
+Cc: stable@vger.kernel.org
+Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
+Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/media/pci/b2c2/flexcop-pci.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/media/pci/b2c2/flexcop-pci.c
++++ b/drivers/media/pci/b2c2/flexcop-pci.c
+@@ -411,7 +411,7 @@ static void flexcop_pci_remove(struct pc
+ struct flexcop_pci *fc_pci = pci_get_drvdata(pdev);
+
+ if (irq_chk_intv > 0)
+- cancel_delayed_work(&fc_pci->irq_check_work);
++ cancel_delayed_work_sync(&fc_pci->irq_check_work);
+
+ flexcop_pci_dma_exit(fc_pci);
+ flexcop_device_exit(fc_pci->fc_dev);
--- /dev/null
+From fa0f61cc1d828178aa921475a9b786e7fbb65ccb Mon Sep 17 00:00:00 2001
+From: Larshin Sergey <Sergey.Larshin@kaspersky.com>
+Date: Tue, 29 Jul 2025 13:13:32 +0300
+Subject: media: rc: fix races with imon_disconnect()
+
+From: Larshin Sergey <Sergey.Larshin@kaspersky.com>
+
+commit fa0f61cc1d828178aa921475a9b786e7fbb65ccb upstream.
+
+Syzbot reports a KASAN issue as below:
+BUG: KASAN: use-after-free in __create_pipe include/linux/usb.h:1945 [inline]
+BUG: KASAN: use-after-free in send_packet+0xa2d/0xbc0 drivers/media/rc/imon.c:627
+Read of size 4 at addr ffff8880256fb000 by task syz-executor314/4465
+
+CPU: 2 PID: 4465 Comm: syz-executor314 Not tainted 6.0.0-rc1-syzkaller #0
+Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
+Call Trace:
+ <TASK>
+__dump_stack lib/dump_stack.c:88 [inline]
+dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
+print_address_description mm/kasan/report.c:317 [inline]
+print_report.cold+0x2ba/0x6e9 mm/kasan/report.c:433
+kasan_report+0xb1/0x1e0 mm/kasan/report.c:495
+__create_pipe include/linux/usb.h:1945 [inline]
+send_packet+0xa2d/0xbc0 drivers/media/rc/imon.c:627
+vfd_write+0x2d9/0x550 drivers/media/rc/imon.c:991
+vfs_write+0x2d7/0xdd0 fs/read_write.c:576
+ksys_write+0x127/0x250 fs/read_write.c:631
+do_syscall_x64 arch/x86/entry/common.c:50 [inline]
+do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
+entry_SYSCALL_64_after_hwframe+0x63/0xcd
+
+The iMON driver improperly releases the usb_device reference in
+imon_disconnect without coordinating with active users of the
+device.
+
+Specifically, the fields usbdev_intf0 and usbdev_intf1 are not
+protected by the users counter (ictx->users). During probe,
+imon_init_intf0 or imon_init_intf1 increments the usb_device
+reference count depending on the interface. However, during
+disconnect, usb_put_dev is called unconditionally, regardless of
+actual usage.
+
+As a result, if vfd_write or other operations are still in
+progress after disconnect, this can lead to a use-after-free of
+the usb_device pointer.
+
+Thread 1 vfd_write Thread 2 imon_disconnect
+ ...
+ if
+ usb_put_dev(ictx->usbdev_intf0)
+ else
+ usb_put_dev(ictx->usbdev_intf1)
+...
+while
+ send_packet
+ if
+ pipe = usb_sndintpipe(
+ ictx->usbdev_intf0) UAF
+ else
+ pipe = usb_sndctrlpipe(
+ ictx->usbdev_intf0, 0) UAF
+
+Guard access to usbdev_intf0 and usbdev_intf1 after disconnect by
+checking ictx->disconnected in all writer paths. Add early return
+with -ENODEV in send_packet(), vfd_write(), lcd_write() and
+display_open() if the device is no longer present.
+
+Set and read ictx->disconnected under ictx->lock to ensure memory
+synchronization. Acquire the lock in imon_disconnect() before setting
+the flag to synchronize with any ongoing operations.
+
+Ensure writers exit early and safely after disconnect before the USB
+core proceeds with cleanup.
+
+Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
+
+Reported-by: syzbot+f1a69784f6efe748c3bf@syzkaller.appspotmail.com
+Closes: https://syzkaller.appspot.com/bug?extid=f1a69784f6efe748c3bf
+Fixes: 21677cfc562a ("V4L/DVB: ir-core: add imon driver")
+Cc: stable@vger.kernel.org
+
+Signed-off-by: Larshin Sergey <Sergey.Larshin@kaspersky.com>
+Signed-off-by: Sean Young <sean@mess.org>
+Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/media/rc/imon.c | 27 ++++++++++++++++++++-------
+ 1 file changed, 20 insertions(+), 7 deletions(-)
+
+--- a/drivers/media/rc/imon.c
++++ b/drivers/media/rc/imon.c
+@@ -536,7 +536,9 @@ static int display_open(struct inode *in
+
+ mutex_lock(&ictx->lock);
+
+- if (!ictx->display_supported) {
++ if (ictx->disconnected) {
++ retval = -ENODEV;
++ } else if (!ictx->display_supported) {
+ pr_err("display not supported by device\n");
+ retval = -ENODEV;
+ } else if (ictx->display_isopen) {
+@@ -598,6 +600,9 @@ static int send_packet(struct imon_conte
+ int retval = 0;
+ struct usb_ctrlrequest *control_req = NULL;
+
++ if (ictx->disconnected)
++ return -ENODEV;
++
+ /* Check if we need to use control or interrupt urb */
+ if (!ictx->tx_control) {
+ pipe = usb_sndintpipe(ictx->usbdev_intf0,
+@@ -954,12 +959,14 @@ static ssize_t vfd_write(struct file *fi
+ static const unsigned char vfd_packet6[] = {
+ 0x01, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF };
+
+- if (ictx->disconnected)
+- return -ENODEV;
+-
+ if (mutex_lock_interruptible(&ictx->lock))
+ return -ERESTARTSYS;
+
++ if (ictx->disconnected) {
++ retval = -ENODEV;
++ goto exit;
++ }
++
+ if (!ictx->dev_present_intf0) {
+ pr_err_ratelimited("no iMON device present\n");
+ retval = -ENODEV;
+@@ -1034,11 +1041,13 @@ static ssize_t lcd_write(struct file *fi
+ int retval = 0;
+ struct imon_context *ictx = file->private_data;
+
+- if (ictx->disconnected)
+- return -ENODEV;
+-
+ mutex_lock(&ictx->lock);
+
++ if (ictx->disconnected) {
++ retval = -ENODEV;
++ goto exit;
++ }
++
+ if (!ictx->display_supported) {
+ pr_err_ratelimited("no iMON display present\n");
+ retval = -ENODEV;
+@@ -2502,7 +2511,11 @@ static void imon_disconnect(struct usb_i
+ int ifnum;
+
+ ictx = usb_get_intfdata(interface);
++
++ mutex_lock(&ictx->lock);
+ ictx->disconnected = true;
++ mutex_unlock(&ictx->lock);
++
+ dev = ictx->dev;
+ ifnum = interface->cur_altsetting->desc.bInterfaceNumber;
+
--- /dev/null
+From 27e06650a5eafe832a90fd2604f0c5e920857fae Mon Sep 17 00:00:00 2001
+From: Wang Haoran <haoranwangsec@gmail.com>
+Date: Sat, 20 Sep 2025 15:44:41 +0800
+Subject: scsi: target: target_core_configfs: Add length check to avoid buffer overflow
+
+From: Wang Haoran <haoranwangsec@gmail.com>
+
+commit 27e06650a5eafe832a90fd2604f0c5e920857fae upstream.
+
+A buffer overflow arises from the usage of snprintf to write into the
+buffer "buf" in target_lu_gp_members_show function located in
+/drivers/target/target_core_configfs.c. This buffer is allocated with
+size LU_GROUP_NAME_BUF (256 bytes).
+
+snprintf(...) formats multiple strings into buf with the HBA name
+(hba->hba_group.cg_item), a slash character, a devicename (dev->
+dev_group.cg_item) and a newline character, the total formatted string
+length may exceed the buffer size of 256 bytes.
+
+Since snprintf() returns the total number of bytes that would have been
+written (the length of %s/%sn ), this value may exceed the buffer length
+(256 bytes) passed to memcpy(), this will ultimately cause function
+memcpy reporting a buffer overflow error.
+
+An additional check of the return value of snprintf() can avoid this
+buffer overflow.
+
+Reported-by: Wang Haoran <haoranwangsec@gmail.com>
+Reported-by: ziiiro <yuanmingbuaa@gmail.com>
+Signed-off-by: Wang Haoran <haoranwangsec@gmail.com>
+Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/target/target_core_configfs.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/target/target_core_configfs.c
++++ b/drivers/target/target_core_configfs.c
+@@ -2637,7 +2637,7 @@ static ssize_t target_lu_gp_members_show
+ config_item_name(&dev->dev_group.cg_item));
+ cur_len++; /* Extra byte for NULL terminator */
+
+- if ((cur_len + len) > PAGE_SIZE) {
++ if ((cur_len + len) > PAGE_SIZE || cur_len > LU_GROUP_NAME_BUF) {
+ pr_warn("Ran out of lu_gp_show_attr"
+ "_members buffer\n");
+ break;
--- /dev/null
+scsi-target-target_core_configfs-add-length-check-to-avoid-buffer-overflow.patch
+media-b2c2-fix-use-after-free-causing-by-irq_check_work-in-flexcop_pci_remove.patch
+media-rc-fix-races-with-imon_disconnect.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
