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authorMauro Carvalho Chehab <mchehab@osg.samsung.com>2016-01-28 09:22:44 -0200
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>2016-02-01 07:16:18 -0200
commit8dfbcc4351a0b6d2f2d77f367552f48ffefafe18 (patch)
tree1bf4b70bd35736ad042982c7b1106ad0314f74b0
parentd83a96a53dd2c36948be37b64a85a761b942ddfd (diff)
[media] xc2028: avoid use after free
If struct xc2028_config is passed without a firmware name, the following trouble may happen: [11009.907205] xc2028 5-0061: type set to XCeive xc2028/xc3028 tuner [11009.907491] ================================================================== [11009.907750] BUG: KASAN: use-after-free in strcmp+0x96/0xb0 at addr ffff8803bd78ab40 [11009.907992] Read of size 1 by task modprobe/28992 [11009.907994] ============================================================================= [11009.907997] BUG kmalloc-16 (Tainted: G W ): kasan: bad access detected [11009.907999] ----------------------------------------------------------------------------- [11009.908008] INFO: Allocated in xhci_urb_enqueue+0x214/0x14c0 [xhci_hcd] age=0 cpu=3 pid=28992 [11009.908012] ___slab_alloc+0x581/0x5b0 [11009.908014] __slab_alloc+0x51/0x90 [11009.908017] __kmalloc+0x27b/0x350 [11009.908022] xhci_urb_enqueue+0x214/0x14c0 [xhci_hcd] [11009.908026] usb_hcd_submit_urb+0x1e8/0x1c60 [11009.908029] usb_submit_urb+0xb0e/0x1200 [11009.908032] usb_serial_generic_write_start+0xb6/0x4c0 [11009.908035] usb_serial_generic_write+0x92/0xc0 [11009.908039] usb_console_write+0x38a/0x560 [11009.908045] call_console_drivers.constprop.14+0x1ee/0x2c0 [11009.908051] console_unlock+0x40d/0x900 [11009.908056] vprintk_emit+0x4b4/0x830 [11009.908061] vprintk_default+0x1f/0x30 [11009.908064] printk+0x99/0xb5 [11009.908067] kasan_report_error+0x10a/0x550 [11009.908070] __asan_report_load1_noabort+0x43/0x50 [11009.908074] INFO: Freed in xc2028_set_config+0x90/0x630 [tuner_xc2028] age=1 cpu=3 pid=28992 [11009.908077] __slab_free+0x2ec/0x460 [11009.908080] kfree+0x266/0x280 [11009.908083] xc2028_set_config+0x90/0x630 [tuner_xc2028] [11009.908086] xc2028_attach+0x310/0x8a0 [tuner_xc2028] [11009.908090] em28xx_attach_xc3028.constprop.7+0x1f9/0x30d [em28xx_dvb] [11009.908094] em28xx_dvb_init.part.3+0x8e4/0x5cf4 [em28xx_dvb] [11009.908098] em28xx_dvb_init+0x81/0x8a [em28xx_dvb] [11009.908101] em28xx_register_extension+0xd9/0x190 [em28xx] [11009.908105] em28xx_dvb_register+0x10/0x1000 [em28xx_dvb] [11009.908108] do_one_initcall+0x141/0x300 [11009.908111] do_init_module+0x1d0/0x5ad [11009.908114] load_module+0x6666/0x9ba0 [11009.908117] SyS_finit_module+0x108/0x130 [11009.908120] entry_SYSCALL_64_fastpath+0x16/0x76 [11009.908123] INFO: Slab 0xffffea000ef5e280 objects=25 used=25 fp=0x (null) flags=0x2ffff8000004080 [11009.908126] INFO: Object 0xffff8803bd78ab40 @offset=2880 fp=0x0000000000000001 [11009.908130] Bytes b4 ffff8803bd78ab30: 01 00 00 00 2a 07 00 00 9d 28 00 00 01 00 00 00 ....*....(...... [11009.908133] Object ffff8803bd78ab40: 01 00 00 00 00 00 00 00 b0 1d c3 6a 00 88 ff ff ...........j.... [11009.908137] CPU: 3 PID: 28992 Comm: modprobe Tainted: G B W 4.5.0-rc1+ #43 [11009.908140] Hardware name: /NUC5i7RYB, BIOS RYBDWi35.86A.0350.2015.0812.1722 08/12/2015 [11009.908142] ffff8803bd78a000 ffff8802c273f1b8 ffffffff81932007 ffff8803c6407a80 [11009.908148] ffff8802c273f1e8 ffffffff81556759 ffff8803c6407a80 ffffea000ef5e280 [11009.908153] ffff8803bd78ab40 dffffc0000000000 ffff8802c273f210 ffffffff8155ccb4 [11009.908158] Call Trace: [11009.908162] [<ffffffff81932007>] dump_stack+0x4b/0x64 [11009.908165] [<ffffffff81556759>] print_trailer+0xf9/0x150 [11009.908168] [<ffffffff8155ccb4>] object_err+0x34/0x40 [11009.908171] [<ffffffff8155f260>] kasan_report_error+0x230/0x550 [11009.908175] [<ffffffff81237d71>] ? trace_hardirqs_off_caller+0x21/0x290 [11009.908179] [<ffffffff8155e926>] ? kasan_unpoison_shadow+0x36/0x50 [11009.908182] [<ffffffff8155f5c3>] __asan_report_load1_noabort+0x43/0x50 [11009.908185] [<ffffffff8155ea00>] ? __asan_register_globals+0x50/0xa0 [11009.908189] [<ffffffff8194cea6>] ? strcmp+0x96/0xb0 [11009.908192] [<ffffffff8194cea6>] strcmp+0x96/0xb0 [11009.908196] [<ffffffffa13ba4ac>] xc2028_set_config+0x15c/0x630 [tuner_xc2028] [11009.908200] [<ffffffffa13bac90>] xc2028_attach+0x310/0x8a0 [tuner_xc2028] [11009.908203] [<ffffffff8155ea78>] ? memset+0x28/0x30 [11009.908206] [<ffffffffa13ba980>] ? xc2028_set_config+0x630/0x630 [tuner_xc2028] [11009.908211] [<ffffffffa157a59a>] em28xx_attach_xc3028.constprop.7+0x1f9/0x30d [em28xx_dvb] [11009.908215] [<ffffffffa157aa2a>] ? em28xx_dvb_init.part.3+0x37c/0x5cf4 [em28xx_dvb] [11009.908219] [<ffffffffa157a3a1>] ? hauppauge_hvr930c_init+0x487/0x487 [em28xx_dvb] [11009.908222] [<ffffffffa01795ac>] ? lgdt330x_attach+0x1cc/0x370 [lgdt330x] [11009.908226] [<ffffffffa01793e0>] ? i2c_read_demod_bytes.isra.2+0x210/0x210 [lgdt330x] [11009.908230] [<ffffffff812e87d0>] ? ref_module.part.15+0x10/0x10 [11009.908233] [<ffffffff812e56e0>] ? module_assert_mutex_or_preempt+0x80/0x80 [11009.908238] [<ffffffffa157af92>] em28xx_dvb_init.part.3+0x8e4/0x5cf4 [em28xx_dvb] [11009.908242] [<ffffffffa157a6ae>] ? em28xx_attach_xc3028.constprop.7+0x30d/0x30d [em28xx_dvb] [11009.908245] [<ffffffff8195222d>] ? string+0x14d/0x1f0 [11009.908249] [<ffffffff8195381f>] ? symbol_string+0xff/0x1a0 [11009.908253] [<ffffffff81953720>] ? uuid_string+0x6f0/0x6f0 [11009.908257] [<ffffffff811a775e>] ? __kernel_text_address+0x7e/0xa0 [11009.908260] [<ffffffff8104b02f>] ? print_context_stack+0x7f/0xf0 [11009.908264] [<ffffffff812e9846>] ? __module_address+0xb6/0x360 [11009.908268] [<ffffffff8137fdc9>] ? is_ftrace_trampoline+0x99/0xe0 [11009.908271] [<ffffffff811a775e>] ? __kernel_text_address+0x7e/0xa0 [11009.908275] [<ffffffff81240a70>] ? debug_check_no_locks_freed+0x290/0x290 [11009.908278] [<ffffffff8104a24b>] ? dump_trace+0x11b/0x300 [11009.908282] [<ffffffffa13e8143>] ? em28xx_register_extension+0x23/0x190 [em28xx] [11009.908285] [<ffffffff81237d71>] ? trace_hardirqs_off_caller+0x21/0x290 [11009.908289] [<ffffffff8123ff56>] ? trace_hardirqs_on_caller+0x16/0x590 [11009.908292] [<ffffffff812404dd>] ? trace_hardirqs_on+0xd/0x10 [11009.908296] [<ffffffffa13e8143>] ? em28xx_register_extension+0x23/0x190 [em28xx] [11009.908299] [<ffffffff822dcbb0>] ? mutex_trylock+0x400/0x400 [11009.908302] [<ffffffff810021a1>] ? do_one_initcall+0x131/0x300 [11009.908306] [<ffffffff81296dc7>] ? call_rcu_sched+0x17/0x20 [11009.908309] [<ffffffff8159e708>] ? put_object+0x48/0x70 [11009.908314] [<ffffffffa1579f11>] em28xx_dvb_init+0x81/0x8a [em28xx_dvb] [11009.908317] [<ffffffffa13e81f9>] em28xx_register_extension+0xd9/0x190 [em28xx] [11009.908320] [<ffffffffa0150000>] ? 0xffffffffa0150000 [11009.908324] [<ffffffffa0150010>] em28xx_dvb_register+0x10/0x1000 [em28xx_dvb] [11009.908327] [<ffffffff810021b1>] do_one_initcall+0x141/0x300 [11009.908330] [<ffffffff81002070>] ? try_to_run_init_process+0x40/0x40 [11009.908333] [<ffffffff8123ff56>] ? trace_hardirqs_on_caller+0x16/0x590 [11009.908337] [<ffffffff8155e926>] ? kasan_unpoison_shadow+0x36/0x50 [11009.908340] [<ffffffff8155e926>] ? kasan_unpoison_shadow+0x36/0x50 [11009.908343] [<ffffffff8155e926>] ? kasan_unpoison_shadow+0x36/0x50 [11009.908346] [<ffffffff8155ea37>] ? __asan_register_globals+0x87/0xa0 [11009.908350] [<ffffffff8144da7b>] do_init_module+0x1d0/0x5ad [11009.908353] [<ffffffff812f2626>] load_module+0x6666/0x9ba0 [11009.908356] [<ffffffff812e9c90>] ? symbol_put_addr+0x50/0x50 [11009.908361] [<ffffffffa1580037>] ? em28xx_dvb_init.part.3+0x5989/0x5cf4 [em28xx_dvb] [11009.908366] [<ffffffff812ebfc0>] ? module_frob_arch_sections+0x20/0x20 [11009.908369] [<ffffffff815bc940>] ? open_exec+0x50/0x50 [11009.908374] [<ffffffff811671bb>] ? ns_capable+0x5b/0xd0 [11009.908377] [<ffffffff812f5e58>] SyS_finit_module+0x108/0x130 [11009.908379] [<ffffffff812f5d50>] ? SyS_init_module+0x1f0/0x1f0 [11009.908383] [<ffffffff81004044>] ? lockdep_sys_exit_thunk+0x12/0x14 [11009.908394] [<ffffffff822e6936>] entry_SYSCALL_64_fastpath+0x16/0x76 [11009.908396] Memory state around the buggy address: [11009.908398] ffff8803bd78aa00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc [11009.908401] ffff8803bd78aa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [11009.908403] >ffff8803bd78ab00: fc fc fc fc fc fc fc fc 00 00 fc fc fc fc fc fc [11009.908405] ^ [11009.908407] ffff8803bd78ab80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [11009.908409] ffff8803bd78ac00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [11009.908411] ================================================================== In order to avoid it, let's set the cached value of the firmware name to NULL after freeing it. While here, return an error if the memory allocation fails. Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
-rw-r--r--drivers/media/tuners/tuner-xc2028.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/media/tuners/tuner-xc2028.c b/drivers/media/tuners/tuner-xc2028.c
index 4e941f0..082ff56 100644
--- a/drivers/media/tuners/tuner-xc2028.c
+++ b/drivers/media/tuners/tuner-xc2028.c
@@ -1403,11 +1403,12 @@ static int xc2028_set_config(struct dvb_frontend *fe, void *priv_cfg)
* in order to avoid troubles during device release.
*/
kfree(priv->ctrl.fname);
+ priv->ctrl.fname = NULL;
memcpy(&priv->ctrl, p, sizeof(priv->ctrl));
if (p->fname) {
priv->ctrl.fname = kstrdup(p->fname, GFP_KERNEL);
if (priv->ctrl.fname == NULL)
- rc = -ENOMEM;
+ return -ENOMEM;
}
/*