From: Jisoo Jang <jisoo.jang@xxxxxxxxxxxx> [ Upstream commit 660145d708be52f946a82e5b633c020f58f996de ] Fix a stack-out-of-bounds read in brcmfmac that occurs when 'buf' that is not null-terminated is passed as an argument of strreplace() in brcmf_c_preinit_dcmds(). This buffer is filled with a CLM version string by memcpy() in brcmf_fil_iovar_data_get(). Ensure buf is null-terminated. Found by a modified version of syzkaller. [ 33.004414][ T1896] brcmfmac: brcmf_c_process_clm_blob: no clm_blob available (err=-2), device may have limited channels available [ 33.013486][ T1896] brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM43236/3 wl0: Nov 30 2011 17:33:42 version 5.90.188.22 [ 33.021554][ T1896] ================================================================== [ 33.022379][ T1896] BUG: KASAN: stack-out-of-bounds in strreplace+0xf2/0x110 [ 33.023122][ T1896] Read of size 1 at addr ffffc90001d6efc8 by task kworker/0:2/1896 [ 33.023852][ T1896] [ 33.024096][ T1896] CPU: 0 PID: 1896 Comm: kworker/0:2 Tainted: G O 5.14.0+ #132 [ 33.024927][ T1896] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 [ 33.026065][ T1896] Workqueue: usb_hub_wq hub_event [ 33.026581][ T1896] Call Trace: [ 33.026896][ T1896] dump_stack_lvl+0x57/0x7d [ 33.027372][ T1896] print_address_description.constprop.0.cold+0xf/0x334 [ 33.028037][ T1896] ? strreplace+0xf2/0x110 [ 33.028403][ T1896] ? strreplace+0xf2/0x110 [ 33.028807][ T1896] kasan_report.cold+0x83/0xdf [ 33.029283][ T1896] ? strreplace+0xf2/0x110 [ 33.029666][ T1896] strreplace+0xf2/0x110 [ 33.029966][ T1896] brcmf_c_preinit_dcmds+0xab1/0xc40 [ 33.030351][ T1896] ? brcmf_c_set_joinpref_default+0x100/0x100 [ 33.030787][ T1896] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 33.031223][ T1896] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 33.031661][ T1896] ? lock_acquire+0x19d/0x4e0 [ 33.032091][ T1896] ? find_held_lock+0x2d/0x110 [ 33.032605][ T1896] ? brcmf_usb_deq+0x1a7/0x260 [ 33.033087][ T1896] ? brcmf_usb_rx_fill_all+0x5a/0xf0 [ 33.033582][ T1896] brcmf_attach+0x246/0xd40 [ 33.034022][ T1896] ? wiphy_new_nm+0x1476/0x1d50 [ 33.034383][ T1896] ? kmemdup+0x30/0x40 [ 33.034722][ T1896] brcmf_usb_probe+0x12de/0x1690 [ 33.035223][ T1896] ? brcmf_usbdev_qinit.constprop.0+0x470/0x470 [ 33.035833][ T1896] usb_probe_interface+0x25f/0x710 [ 33.036315][ T1896] really_probe+0x1be/0xa90 [ 33.036656][ T1896] __driver_probe_device+0x2ab/0x460 [ 33.037026][ T1896] ? usb_match_id.part.0+0x88/0xc0 [ 33.037383][ T1896] driver_probe_device+0x49/0x120 [ 33.037790][ T1896] __device_attach_driver+0x18a/0x250 [ 33.038300][ T1896] ? driver_allows_async_probing+0x120/0x120 [ 33.038986][ T1896] bus_for_each_drv+0x123/0x1a0 [ 33.039906][ T1896] ? bus_rescan_devices+0x20/0x20 [ 33.041412][ T1896] ? lockdep_hardirqs_on_prepare+0x273/0x3e0 [ 33.041861][ T1896] ? trace_hardirqs_on+0x1c/0x120 [ 33.042330][ T1896] __device_attach+0x207/0x330 [ 33.042664][ T1896] ? device_bind_driver+0xb0/0xb0 [ 33.043026][ T1896] ? kobject_uevent_env+0x230/0x12c0 [ 33.043515][ T1896] bus_probe_device+0x1a2/0x260 [ 33.043914][ T1896] device_add+0xa61/0x1ce0 [ 33.044227][ T1896] ? __mutex_unlock_slowpath+0xe7/0x660 [ 33.044891][ T1896] ? __fw_devlink_link_to_suppliers+0x550/0x550 [ 33.045531][ T1896] usb_set_configuration+0x984/0x1770 [ 33.046051][ T1896] ? kernfs_create_link+0x175/0x230 [ 33.046548][ T1896] usb_generic_driver_probe+0x69/0x90 [ 33.046931][ T1896] usb_probe_device+0x9c/0x220 [ 33.047434][ T1896] really_probe+0x1be/0xa90 [ 33.047760][ T1896] __driver_probe_device+0x2ab/0x460 [ 33.048134][ T1896] driver_probe_device+0x49/0x120 [ 33.048516][ T1896] __device_attach_driver+0x18a/0x250 [ 33.048910][ T1896] ? driver_allows_async_probing+0x120/0x120 [ 33.049437][ T1896] bus_for_each_drv+0x123/0x1a0 [ 33.049814][ T1896] ? bus_rescan_devices+0x20/0x20 [ 33.050164][ T1896] ? lockdep_hardirqs_on_prepare+0x273/0x3e0 [ 33.050579][ T1896] ? trace_hardirqs_on+0x1c/0x120 [ 33.050936][ T1896] __device_attach+0x207/0x330 [ 33.051399][ T1896] ? device_bind_driver+0xb0/0xb0 [ 33.051888][ T1896] ? kobject_uevent_env+0x230/0x12c0 [ 33.052314][ T1896] bus_probe_device+0x1a2/0x260 [ 33.052688][ T1896] device_add+0xa61/0x1ce0 [ 33.053121][ T1896] ? __fw_devlink_link_to_suppliers+0x550/0x550 [ 33.053568][ T1896] usb_new_device.cold+0x463/0xf66 [ 33.053953][ T1896] ? hub_disconnect+0x400/0x400 [ 33.054313][ T1896] ? rwlock_bug.part.0+0x90/0x90 [ 33.054661][ T1896] ? lockdep_hardirqs_on_prepare+0x273/0x3e0 [ 33.055094][ T1896] hub_event+0x10d5/0x3330 [ 33.055530][ T1896] ? hub_port_debounce+0x280/0x280 [ 33.055934][ T1896] ? __lock_acquire+0x1671/0x5790 [ 33.056387][ T1896] ? wq_calc_node_cpumask+0x170/0x2a0 [ 33.056924][ T1896] ? lock_release+0x640/0x640 [ 33.057383][ T1896] ? rcu_read_lock_sched_held+0xa1/0xd0 [ 33.057916][ T1896] ? rcu_read_lock_bh_held+0xb0/0xb0 [ 33.058402][ T1896] ? lockdep_hardirqs_on_prepare+0x273/0x3e0 [ 33.059019][ T1896] process_one_work+0x873/0x13e0 [ 33.059488][ T1896] ? lock_release+0x640/0x640 [ 33.059932][ T1896] ? pwq_dec_nr_in_flight+0x320/0x320 [ 33.060446][ T1896] ? rwlock_bug.part.0+0x90/0x90 [ 33.060898][ T1896] worker_thread+0x8b/0xd10 [ 33.061348][ T1896] ? __kthread_parkme+0xd9/0x1d0 [ 33.061810][ T1896] ? process_one_work+0x13e0/0x13e0 [ 33.062288][ T1896] kthread+0x379/0x450 [ 33.062660][ T1896] ? _raw_spin_unlock_irq+0x24/0x30 [ 33.063148][ T1896] ? set_kthread_struct+0x100/0x100 [ 33.063606][ T1896] ret_from_fork+0x1f/0x30 [ 33.064070][ T1896] [ 33.064313][ T1896] [ 33.064545][ T1896] addr ffffc90001d6efc8 is located in stack of task kworker/0:2/1896 at offset 512 in frame: [ 33.065478][ T1896] brcmf_c_preinit_dcmds+0x0/0xc40 [ 33.065973][ T1896] [ 33.066191][ T1896] this frame has 4 objects: [ 33.066614][ T1896] [48, 56) 'ptr' [ 33.066618][ T1896] [80, 148) 'revinfo' [ 33.066957][ T1896] [192, 210) 'eventmask' [ 33.067338][ T1896] [256, 512) 'buf' [ 33.067742][ T1896] [ 33.068304][ T1896] Memory state around the buggy address: [ 33.068838][ T1896] ffffc90001d6ee80: f2 00 00 02 f2 f2 f2 f2 f2 00 00 00 00 00 00 00 [ 33.069545][ T1896] ffffc90001d6ef00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 33.070626][ T1896] >ffffc90001d6ef80: 00 00 00 00 00 00 00 00 00 f3 f3 f3 f3 f3 f3 f3 [ 33.072052][ T1896] ^ [ 33.073043][ T1896] ffffc90001d6f000: f3 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 33.074230][ T1896] ffffc90001d6f080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 33.074914][ T1896] ================================================================== [ 33.075713][ T1896] Disabling lock debugging due to kernel taint Reviewed-by: Arend van Spriel<arend.vanspriel@xxxxxxxxxxxx> Signed-off-by: Jisoo Jang <jisoo.jang@xxxxxxxxxxxx> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx> Link: https://lore.kernel.org/r/20221230075139.56591-1-jisoo.jang@xxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c index 789930806d03a..fc5232a896535 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/common.c @@ -319,15 +319,17 @@ int brcmf_c_preinit_dcmds(struct brcmf_if *ifp) if (err) { brcmf_dbg(TRACE, "retrieving clmver failed, %d\n", err); } else { + buf[sizeof(buf) - 1] = '\0'; clmver = (char *)buf; - /* store CLM version for adding it to revinfo debugfs file */ - memcpy(ifp->drvr->clmver, clmver, sizeof(ifp->drvr->clmver)); /* Replace all newline/linefeed characters with space * character */ strreplace(clmver, '\n', ' '); + /* store CLM version for adding it to revinfo debugfs file */ + memcpy(ifp->drvr->clmver, clmver, sizeof(ifp->drvr->clmver)); + brcmf_dbg(INFO, "CLM version = %s\n", clmver); } -- 2.39.0
