683b9728f2
This patch fixes a NULL pointer dereference bug in brcmfmac that occurs when ptr which is NULL pointer passed as an argument of strlcpy() in brcmf_c_preinit_dcmds(). This happens when the driver passes a firmware version string that does not contain a space " ", making strrchr() return a null pointer. This patch adds a null pointer check. Found by a modified version of syzkaller. KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 1983 Comm: kworker/0:2 Not tainted 5.14.0+ #79 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 Workqueue: usb_hub_wq hub_event RIP: 0010:strlen+0x1a/0x90 Code: 23 ff ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 90 48 b8 00 00 00 00 00 fc ff df 48 89 fa 55 48 89 fd 48 c1 ea 03 53 48 83 ec 08 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 48 80 7d 00 00 RSP: 0018:ffffc90002bfedd8 EFLAGS: 00010296 RAX: dffffc0000000000 RBX: 1ffff9200057fdc1 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000020 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000039 R09: ffffed1023549801 R10: ffff88811aa4c007 R11: ffffed1023549800 R12: ffff88800bc68d6c R13: ffffc90002bfef08 R14: ffff88800bc6bc7c R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88811aa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020546180 CR3: 0000000117ff1000 CR4: 0000000000750ef0 PKRU: 55555554 Call Trace: brcmf_c_preinit_dcmds+0x9f2/0xc40 ? brcmf_c_set_joinpref_default+0x100/0x100 ? rcu_read_lock_sched_held+0xa1/0xd0 ? rcu_read_lock_bh_held+0xb0/0xb0 ? lock_acquire+0x19d/0x4e0 ? find_held_lock+0x2d/0x110 ? brcmf_usb_deq+0x1a7/0x260 ? brcmf_usb_rx_fill_all+0x5a/0xf0 brcmf_attach+0x246/0xd40 ? wiphy_new_nm+0x1703/0x1dd0 ? kmemdup+0x43/0x50 brcmf_usb_probe+0x12de/0x1690 ? brcmf_usbdev_qinit.constprop.0+0x470/0x470 usb_probe_interface+0x2aa/0x760 ? usb_probe_device+0x250/0x250 really_probe+0x205/0xb70 ? driver_allows_async_probing+0x130/0x130 __driver_probe_device+0x311/0x4b0 ? driver_allows_async_probing+0x130/0x130 driver_probe_device+0x4e/0x150 __device_attach_driver+0x1cc/0x2a0 bus_for_each_drv+0x156/0x1d0 ? bus_rescan_devices+0x30/0x30 ? lockdep_hardirqs_on_prepare+0x273/0x3e0 ? trace_hardirqs_on+0x46/0x160 __device_attach+0x23f/0x3a0 ? device_bind_driver+0xd0/0xd0 ? kobject_uevent_env+0x287/0x14b0 bus_probe_device+0x1da/0x290 device_add+0xb7b/0x1eb0 ? wait_for_completion+0x290/0x290 ? __fw_devlink_link_to_suppliers+0x5a0/0x5a0 usb_set_configuration+0xf59/0x16f0 usb_generic_driver_probe+0x82/0xa0 usb_probe_device+0xbb/0x250 ? usb_suspend+0x590/0x590 really_probe+0x205/0xb70 ? driver_allows_async_probing+0x130/0x130 __driver_probe_device+0x311/0x4b0 ? usb_generic_driver_match+0x75/0x90 ? driver_allows_async_probing+0x130/0x130 driver_probe_device+0x4e/0x150 __device_attach_driver+0x1cc/0x2a0 bus_for_each_drv+0x156/0x1d0 ? bus_rescan_devices+0x30/0x30 ? _raw_spin_unlock_irqrestore+0x47/0x50 __device_attach+0x23f/0x3a0 ? device_bind_driver+0xd0/0xd0 ? kobject_uevent_env+0x287/0x14b0 bus_probe_device+0x1da/0x290 device_add+0xb7b/0x1eb0 ? __fw_devlink_link_to_suppliers+0x5a0/0x5a0 ? kfree+0x14a/0x6b0 ? __usb_get_extra_descriptor+0x116/0x160 usb_new_device.cold+0x49c/0x1029 ? hub_disconnect+0x450/0x450 ? rwlock_bug.part.0+0x90/0x90 ? _raw_spin_unlock_irq+0x24/0x30 ? lockdep_hardirqs_on_prepare+0x273/0x3e0 hub_event+0x248b/0x31c9 ? usb_port_suspend.cold+0x139/0x139 ? check_irq_usage+0x861/0xf20 ? drain_workqueue+0x280/0x360 ? lock_release+0x640/0x640 ? rcu_read_lock_sched_held+0xa1/0xd0 ? rcu_read_lock_bh_held+0xb0/0xb0 ? lockdep_hardirqs_on_prepare+0x273/0x3e0 process_one_work+0x92b/0x1460 ? pwq_dec_nr_in_flight+0x330/0x330 ? rwlock_bug.part.0+0x90/0x90 worker_thread+0x95/0xe00 ? __kthread_parkme+0x115/0x1e0 ? process_one_work+0x1460/0x1460 kthread+0x3a1/0x480 ? set_kthread_struct+0x120/0x120 ret_from_fork+0x1f/0x30 Modulesdd linked in: ---[ end trace c112c68924ddd800 ]--- RIP: 0010:strlen+0x1a/0x90 Code: 23 ff ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 90 48 b8 00 00 00 00 00 fc ff df 48 89 fa 55 48 89 fd 48 c1 ea 03 53 48 83 ec 08 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 48 80 7d 00 00 RSP: 0018:ffffc90002bfedd8 EFLAGS: 00010296 RAX: dffffc0000000000 RBX: 1ffff9200057fdc1 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000020 RDI: 0000000000000001 RBP: 0000000000000001 R08: 0000000000000039 R09: ffffed1023549801 R10: ffff88811aa4c007 R11: ffffed1023549800 R12: ffff88800bc68d6c R13: ffffc90002bfef08 R14: ffff88800bc6bc7c R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88811aa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020546180 CR3: 0000000117ff1000 CR4: 0000000000750ef0 PKRU: 55555554 Kernel panic - not syncing: Fatal exception Kernel Offset: disabled Reported-by: Dokyung Song <dokyungs@yonsei.ac.kr> Reported-by: Jisoo Jang <jisoo.jang@yonsei.ac.kr> Reported-by: Minsuk Kang <linuxlovemin@yonsei.ac.kr> Signed-off-by: Jisoo Jang <jisoo.jang@yonsei.ac.kr> Signed-off-by: Kalle Valo <kvalo@kernel.org> Link: https://lore.kernel.org/r/20221101183642.166450-1-jisoo.jang@yonsei.ac.kr
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.