Re: [PATCH] Input: walkera0701 - Fix possible NULL pointer dereference in walkera0701_detach
From: YueHaibing
Date: Thu May 16 2019 - 22:40:46 EST
ping...
On 2019/4/23 22:56, Yue Haibing wrote:
> From: YueHaibing <yuehaibing@xxxxxxxxxx>
>
> KASAN report this:
>
> walkera0701: failed to allocate input device
> kasan: CONFIG_KASAN_INLINE enabled
> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault: 0000 [#1] SMP KASAN PTI
> CPU: 1 PID: 5324 Comm: syz-executor.0 Tainted: G C 5.1.0-rc3+ #8
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
> RIP: 0010:input_unregister_device+0x21/0xe0 drivers/input/input.c:2192
> Code: 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 07 41 f6 fe 48 8d bb 20 07 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 84 c0 0f 8e 92 00 00 00 80 bb 20 07 00 00
> RSP: 0018:ffff8881f58dfd30 EFLAGS: 00010206
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff82460ca9
> RDX: 00000000000000e4 RSI: ffffc900013d3000 RDI: 0000000000000720
> RBP: 0000000000000000 R08: ffffed103d30caf7 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
> R13: ffffffffc1633000 R14: ffffffffc086b320 R15: 1ffff1103eb1bfaf
> FS: 00007fa407200700(0000) GS:ffff8881f7300000(0000) knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 0000001b33924000 CR3: 00000001e270c006 CR4: 00000000007606e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> PKRU: 55555554
> Call Trace:
> walkera0701_detach+0x8e/0xba [walkera0701]
> port_detach+0x73/0x90 [parport]
> bus_for_each_dev+0x154/0x1e0 drivers/base/bus.c:304
> parport_unregister_driver+0x1f8/0x270 [parport]
> __do_sys_delete_module kernel/module.c:1018 [inline]
> __se_sys_delete_module kernel/module.c:961 [inline]
> __x64_sys_delete_module+0x30c/0x480 kernel/module.c:961
> do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x462e99
> Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 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 bc ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007fa4071ffc58 EFLAGS: 00000246 ORIG_RAX: 00000000000000b0
> RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0
> RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa4072006bc
> R13: 00000000004bcca9 R14: 00000000006f6b48 R15: 00000000ffffffff
> Modules linked in: walkera0701(-) tps65090_regulator intel_th mptbase adm1031 snd_soc_wm8753 snd_soc_core snd_pcm_dmaengine snd_pcm ac97_bus snd_compress rtc_ds1286 snd_seq_dummy snd_seq snd_timer snd_seq_device snd soundcore comedi(C) i2c_mux_ltc4306 i2c_mux max14577_regulator max14577 usbcore hid cmac mc13783_regulator mc13xxx_regulator_core mc13xxx_core of_mdio fixed_phy libphy iptable_security iptable_raw iptable_mangle iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bpfilter ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel hsr veth netdevsim vxcan batman_adv cfg80211 rfkill chnl_net caif nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun joydev mousedev ppdev tpm kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel ide_pci_generic aesni_intel aes_x86_64 piix crypto_simd cryptd input_leds ide_core psmouse glue_helper intel_agp serio_raw intel_gtt ata_generic agpgart i2c_piix4
> pata_acpi parport_pc parport floppy rtc_cmos sch_fq_codel ip_tables x_tables sha1_ssse3 sha1_generic ipv6 [last unloaded: walkera0701]
> Dumping ftrace buffer:
> (ftrace buffer empty)
> ---[ end trace 17f6dd401f34af3e ]---
>
> In walkera0701_attach(), if input_allocate_device failed,
> w->input_dev is set to NULL. But in walkera0701_detach it
> is not checked while passing to input_unregister_device(),
> this will trigger a NULL pointer dereference issue.
>
> There is also another possible use-after-free issue, when
> input_register_device() fails, input_free_device be
> called to free input dev, then in walkera0701_detach()
> calling input_unregister_device will trigger use-after-free
> while accessing input dev
>
> This patch set w->parport to NULL on walkera0701_attach failed,
> and only do detach in case attach success.
>
> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
> Fixes: 221bcb24c653 ("Input: walkera0701 - use parallel port device model")
> Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
> ---
> drivers/input/joystick/walkera0701.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/input/joystick/walkera0701.c b/drivers/input/joystick/walkera0701.c
> index dce313d..852b8c5 100644
> --- a/drivers/input/joystick/walkera0701.c
> +++ b/drivers/input/joystick/walkera0701.c
> @@ -207,13 +207,13 @@ static void walkera0701_attach(struct parport *pp)
>
> if (pp->number != walkera0701_pp_no) {
> pr_debug("Not using parport%d.\n", pp->number);
> - return;
> + goto err_out;
> }
>
> if (pp->irq == -1) {
> pr_err("parport %d does not have interrupt assigned\n",
> pp->number);
> - return;
> + goto err_out;
> }
>
> w->parport = pp;
> @@ -228,7 +228,7 @@ static void walkera0701_attach(struct parport *pp)
>
> if (!w->pardevice) {
> pr_err("failed to register parport device\n");
> - return;
> + goto err_out;
> }
>
> if (parport_negotiate(w->pardevice->port, IEEE1284_MODE_COMPAT)) {
> @@ -279,13 +279,15 @@ static void walkera0701_attach(struct parport *pp)
> input_free_device(w->input_dev);
> err_unregister_device:
> parport_unregister_device(w->pardevice);
> +err_out:
> + w->parport = NULL;
> }
>
> static void walkera0701_detach(struct parport *port)
> {
> struct walkera_dev *w = &w_dev;
>
> - if (!w->pardevice || w->parport->number != port->number)
> + if (!w->parport)
> return;
>
> input_unregister_device(w->input_dev);
>