linux-stable.git/drivers/usb, branch v5.16.2 Linux kernel stable tree USB: Fix "slab-out-of-bounds Write" bug in usb_hcd_poll_rh_status 2022-01-16T08:11:13+00:00 Alan Stern stern@rowland.harvard.edu 2022-01-01T02:07:12+00:00 c0aa87faf5e0794672a8b82cae2b0fadbdb90e7e commit 1d7d4c07932e04355d6e6528d44a2f2c9e354346 upstream. When the USB core code for getting root-hub status reports was originally written, it was assumed that the hub driver would be its only caller. But this isn't true now; user programs can use usbfs to communicate with root hubs and get status reports. When they do this, they may use a transfer_buffer that is smaller than the data returned by the HCD, which will lead to a buffer overflow error when usb_hcd_poll_rh_status() tries to store the status data. This was discovered by syzbot: BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline] BUG: KASAN: slab-out-of-bounds in usb_hcd_poll_rh_status+0x5f4/0x780 drivers/usb/core/hcd.c:776 Write of size 2 at addr ffff88801da403c0 by task syz-executor133/4062 This patch fixes the bug by reducing the amount of status data if it won't fit in the transfer_buffer. If some data gets discarded then the URB's completion status is set to -EOVERFLOW rather than 0, to let the user know what happened. Reported-and-tested-by: syzbot+3ae6a2b06f131ab9849f@syzkaller.appspotmail.com Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/Yc+3UIQJ2STbxNua@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1d7d4c07932e04355d6e6528d44a2f2c9e354346 upstream.

When the USB core code for getting root-hub status reports was
originally written, it was assumed that the hub driver would be its
only caller.  But this isn't true now; user programs can use usbfs to
communicate with root hubs and get status reports.  When they do this,
they may use a transfer_buffer that is smaller than the data returned
by the HCD, which will lead to a buffer overflow error when
usb_hcd_poll_rh_status() tries to store the status data.  This was
discovered by syzbot:

BUG: KASAN: slab-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline]
BUG: KASAN: slab-out-of-bounds in usb_hcd_poll_rh_status+0x5f4/0x780 drivers/usb/core/hcd.c:776
Write of size 2 at addr ffff88801da403c0 by task syz-executor133/4062

This patch fixes the bug by reducing the amount of status data if it
won't fit in the transfer_buffer.  If some data gets discarded then
the URB's completion status is set to -EOVERFLOW rather than 0, to let
the user know what happened.

Reported-and-tested-by: syzbot+3ae6a2b06f131ab9849f@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/Yc+3UIQJ2STbxNua@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB: core: Fix bug in resuming hub's handling of wakeup requests 2022-01-16T08:11:13+00:00 Alan Stern stern@rowland.harvard.edu 2022-01-01T19:52:14+00:00 64198e9031cdb78aa51cb5d42d19766f5313e067 commit 0f663729bb4afc92a9986b66131ebd5b8a9254d1 upstream. Bugzilla #213839 reports a 7-port hub that doesn't work properly when devices are plugged into some of the ports; the kernel goes into an unending disconnect/reinitialize loop as shown in the bug report. This "7-port hub" comprises two four-port hubs with one plugged into the other; the failures occur when a device is plugged into one of the downstream hub's ports. (These hubs have other problems too. For example, they bill themselves as USB-2.0 compliant but they only run at full speed.) It turns out that the failures are caused by bugs in both the kernel and the hub. The hub's bug is that it reports a different bmAttributes value in its configuration descriptor following a remote wakeup (0xe0 before, 0xc0 after -- the wakeup-support bit has changed). The kernel's bug is inside the hub driver's resume handler. When hub_activate() sees that one of the hub's downstream ports got a wakeup request from a child device, it notes this fact by setting the corresponding bit in the hub->change_bits variable. But this variable is meant for connection changes, not wakeup events; setting it causes the driver to believe the downstream port has been disconnected and then connected again (in addition to having received a wakeup request). Because of this, the hub driver then tries to check whether the device currently plugged into the downstream port is the same as the device that had been attached there before. Normally this check succeeds and wakeup handling continues with no harm done (which is why the bug remained undetected until now). But with these dodgy hubs, the check fails because the config descriptor has changed. This causes the hub driver to reinitialize the child device, leading to the disconnect/reinitialize loop described in the bug report. The proper way to note reception of a downstream wakeup request is to set a bit in the hub->event_bits variable instead of hub->change_bits. That way the hub driver will realize that something has happened to the port but will not think the port and child device have been disconnected. This patch makes that change. Cc: <stable@vger.kernel.org> Tested-by: Jonathan McDowell <noodles@earth.li> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Link: https://lore.kernel.org/r/YdCw7nSfWYPKWQoD@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0f663729bb4afc92a9986b66131ebd5b8a9254d1 upstream.

Bugzilla #213839 reports a 7-port hub that doesn't work properly when
devices are plugged into some of the ports; the kernel goes into an
unending disconnect/reinitialize loop as shown in the bug report.

This "7-port hub" comprises two four-port hubs with one plugged into
the other; the failures occur when a device is plugged into one of the
downstream hub's ports.  (These hubs have other problems too.  For
example, they bill themselves as USB-2.0 compliant but they only run
at full speed.)

It turns out that the failures are caused by bugs in both the kernel
and the hub.  The hub's bug is that it reports a different
bmAttributes value in its configuration descriptor following a remote
wakeup (0xe0 before, 0xc0 after -- the wakeup-support bit has
changed).

The kernel's bug is inside the hub driver's resume handler.  When
hub_activate() sees that one of the hub's downstream ports got a
wakeup request from a child device, it notes this fact by setting the
corresponding bit in the hub->change_bits variable.  But this variable
is meant for connection changes, not wakeup events; setting it causes
the driver to believe the downstream port has been disconnected and
then connected again (in addition to having received a wakeup
request).

Because of this, the hub driver then tries to check whether the device
currently plugged into the downstream port is the same as the device
that had been attached there before.  Normally this check succeeds and
wakeup handling continues with no harm done (which is why the bug
remained undetected until now).  But with these dodgy hubs, the check
fails because the config descriptor has changed.  This causes the hub
driver to reinitialize the child device, leading to the
disconnect/reinitialize loop described in the bug report.

The proper way to note reception of a downstream wakeup request is
to set a bit in the hub->event_bits variable instead of
hub->change_bits.  That way the hub driver will realize that something
has happened to the port but will not think the port and child device
have been disconnected.  This patch makes that change.

Cc: <stable@vger.kernel.org>
Tested-by: Jonathan McDowell <noodles@earth.li>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/YdCw7nSfWYPKWQoD@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: ucsi: Only check the contract if there is a connection 2021-12-21T15:30:53+00:00 Heikki Krogerus heikki.krogerus@linux.intel.com 2021-12-21T14:03:52+00:00 3f345e907a8e7c56fdebf7231cd67afc85d02aaa The driver must make sure there is an actual connection before checking details about the USB Power Delivery contract. Those details are not valid unless there is a connection. This fixes NULL pointer dereference that is caused by an attempt to register bogus partner alternate mode that the firmware on some platform may report before the actual connection. Link: https://bugzilla.kernel.org/show_bug.cgi?id=215117 Fixes: 6cbe4b2d5a3f ("usb: typec: ucsi: Check the partner alt modes always if there is PD contract") Reported-by: Chris Hixon <linux-kernel-bugs@hixontech.com> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/eb34f98f-00ef-3238-2daa-80481116035d@leemhuis.info/ Link: https://lore.kernel.org/r/20211221140352.45501-1-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The driver must make sure there is an actual connection
before checking details about the USB Power Delivery
contract. Those details are not valid unless there is a
connection.

This fixes NULL pointer dereference that is caused by an
attempt to register bogus partner alternate mode that the
firmware on some platform may report before the actual
connection.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=215117
Fixes: 6cbe4b2d5a3f ("usb: typec: ucsi: Check the partner alt modes always if there is PD contract")
Reported-by: Chris Hixon <linux-kernel-bugs@hixontech.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/eb34f98f-00ef-3238-2daa-80481116035d@leemhuis.info/
Link: https://lore.kernel.org/r/20211221140352.45501-1-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xhci: Fresco FL1100 controller should not have BROKEN_MSI quirk set. 2021-12-21T11:38:33+00:00 Mathias Nyman mathias.nyman@linux.intel.com 2021-12-21T11:28:25+00:00 e4844092581ceec22489b66c42edc88bc6079783 The Fresco Logic FL1100 controller needs the TRUST_TX_LENGTH quirk like other Fresco controllers, but should not have the BROKEN_MSI quirks set. BROKEN_MSI quirk causes issues in detecting usb drives connected to docks with this FL1100 controller. The BROKEN_MSI flag was apparently accidentally set together with the TRUST_TX_LENGTH quirk Original patch went to stable so this should go there as well. Fixes: ea0f69d82119 ("xhci: Enable trust tx length quirk for Fresco FL11 USB controller") Cc: stable@vger.kernel.org cc: Nikolay Martynov <mar.kolya@gmail.com> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> Link: https://lore.kernel.org/r/20211221112825.54690-2-mathias.nyman@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The Fresco Logic FL1100 controller needs the TRUST_TX_LENGTH quirk like
other Fresco controllers, but should not have the BROKEN_MSI quirks set.

BROKEN_MSI quirk causes issues in detecting usb drives connected to docks
with this FL1100 controller.
The BROKEN_MSI flag was apparently accidentally set together with the
TRUST_TX_LENGTH quirk

Original patch went to stable so this should go there as well.

Fixes: ea0f69d82119 ("xhci: Enable trust tx length quirk for Fresco FL11 USB controller")
Cc: stable@vger.kernel.org
cc: Nikolay Martynov <mar.kolya@gmail.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20211221112825.54690-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: mtu3: set interval of FS intr and isoc endpoint 2021-12-21T08:05:45+00:00 Chunfeng Yun chunfeng.yun@mediatek.com 2021-12-18T09:57:49+00:00 43f3b8cbcf93da7c2755af4a543280c31f4adf16 Add support to set interval also for FS intr and isoc endpoint. Fixes: 4d79e042ed8b ("usb: mtu3: add support for usb3.1 IP") Cc: stable@vger.kernel.org Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Link: https://lore.kernel.org/r/20211218095749.6250-4-chunfeng.yun@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Add support to set interval also for FS intr and isoc endpoint.

Fixes: 4d79e042ed8b ("usb: mtu3: add support for usb3.1 IP")
Cc: stable@vger.kernel.org
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20211218095749.6250-4-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: mtu3: fix list_head check warning 2021-12-21T08:05:45+00:00 Chunfeng Yun chunfeng.yun@mediatek.com 2021-12-18T09:57:48+00:00 8c313e3bfd9adae8d5c4ba1cc696dcbc86fbf9bf This is caused by uninitialization of list_head. BUG: KASAN: use-after-free in __list_del_entry_valid+0x34/0xe4 Call trace: dump_backtrace+0x0/0x298 show_stack+0x24/0x34 dump_stack+0x130/0x1a8 print_address_description+0x88/0x56c __kasan_report+0x1b8/0x2a0 kasan_report+0x14/0x20 __asan_load8+0x9c/0xa0 __list_del_entry_valid+0x34/0xe4 mtu3_req_complete+0x4c/0x300 [mtu3] mtu3_gadget_stop+0x168/0x448 [mtu3] usb_gadget_unregister_driver+0x204/0x3a0 unregister_gadget_item+0x44/0xa4 Fixes: 83374e035b62 ("usb: mtu3: add tracepoints to help debug") Cc: stable@vger.kernel.org Reported-by: Yuwen Ng <yuwen.ng@mediatek.com> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Link: https://lore.kernel.org/r/20211218095749.6250-3-chunfeng.yun@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This is caused by uninitialization of list_head.

BUG: KASAN: use-after-free in __list_del_entry_valid+0x34/0xe4

Call trace:
dump_backtrace+0x0/0x298
show_stack+0x24/0x34
dump_stack+0x130/0x1a8
print_address_description+0x88/0x56c
__kasan_report+0x1b8/0x2a0
kasan_report+0x14/0x20
__asan_load8+0x9c/0xa0
__list_del_entry_valid+0x34/0xe4
mtu3_req_complete+0x4c/0x300 [mtu3]
mtu3_gadget_stop+0x168/0x448 [mtu3]
usb_gadget_unregister_driver+0x204/0x3a0
unregister_gadget_item+0x44/0xa4

Fixes: 83374e035b62 ("usb: mtu3: add tracepoints to help debug")
Cc: stable@vger.kernel.org
Reported-by: Yuwen Ng <yuwen.ng@mediatek.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20211218095749.6250-3-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: mtu3: add memory barrier before set GPD's HWO 2021-12-21T08:05:44+00:00 Chunfeng Yun chunfeng.yun@mediatek.com 2021-12-18T09:57:47+00:00 a7aae769ca626819a7f9f078ebdc69a8a1b00c81 There is a seldom issue that the controller access invalid address and trigger devapc or emimpu violation. That is due to memory access is out of order and cause gpd data is not correct. Add mb() to prohibit compiler or cpu from reordering to make sure GPD is fully written before setting its HWO. Fixes: 48e0d3735aa5 ("usb: mtu3: supports new QMU format") Cc: stable@vger.kernel.org Reported-by: Eddie Hung <eddie.hung@mediatek.com> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Link: https://lore.kernel.org/r/20211218095749.6250-2-chunfeng.yun@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
There is a seldom issue that the controller access invalid address
and trigger devapc or emimpu violation. That is due to memory access
is out of order and cause gpd data is not correct.
Add mb() to prohibit compiler or cpu from reordering to make sure GPD
is fully written before setting its HWO.

Fixes: 48e0d3735aa5 ("usb: mtu3: supports new QMU format")
Cc: stable@vger.kernel.org
Reported-by: Eddie Hung <eddie.hung@mediatek.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20211218095749.6250-2-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: mtu3: fix interval value for intr and isoc 2021-12-21T08:05:44+00:00 Chunfeng Yun chunfeng.yun@mediatek.com 2021-12-18T09:57:46+00:00 e3d4621c22f90c33321ae6a6baab60cdb8e5a77c Use the Interval value from isoc/intr endpoint descriptor, no need minus one. The original code doesn't cause transfer error for normal cases, but it may have side effect with respond time of ERDY or tPingTimeout. Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com> Link: https://lore.kernel.org/r/20211218095749.6250-1-chunfeng.yun@mediatek.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Use the Interval value from isoc/intr endpoint descriptor, no need
minus one. The original code doesn't cause transfer error for
normal cases, but it may have side effect with respond time of ERDY
or tPingTimeout.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/20211218095749.6250-1-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: gadget: f_fs: Clear ffs_eventfd in ffs_data_clear. 2021-12-21T08:05:21+00:00 Vincent Pelletier plr.vincent@gmail.com 2021-12-18T02:18:40+00:00 b1e0887379422975f237d43d8839b751a6bcf154 ffs_data_clear is indirectly called from both ffs_fs_kill_sb and ffs_ep0_release, so it ends up being called twice when userland closes ep0 and then unmounts f_fs. If userland provided an eventfd along with function's USB descriptors, it ends up calling eventfd_ctx_put as many times, causing a refcount underflow. NULL-ify ffs_eventfd to prevent these extraneous eventfd_ctx_put calls. Also, set epfiles to NULL right after de-allocating it, for readability. For completeness, ffs_data_clear actually ends up being called thrice, the last call being before the whole ffs structure gets freed, so when this specific sequence happens there is a second underflow happening (but not being reported): /sys/kernel/debug/tracing# modprobe usb_f_fs /sys/kernel/debug/tracing# echo ffs_data_clear > set_ftrace_filter /sys/kernel/debug/tracing# echo function > current_tracer /sys/kernel/debug/tracing# echo 1 > tracing_on (setup gadget, run and kill function userland process, teardown gadget) /sys/kernel/debug/tracing# echo 0 > tracing_on /sys/kernel/debug/tracing# cat trace smartcard-openp-436 [000] ..... 1946.208786: ffs_data_clear <-ffs_data_closed smartcard-openp-431 [000] ..... 1946.279147: ffs_data_clear <-ffs_data_closed smartcard-openp-431 [000] .n... 1946.905512: ffs_data_clear <-ffs_data_put Warning output corresponding to above trace: [ 1946.284139] WARNING: CPU: 0 PID: 431 at lib/refcount.c:28 refcount_warn_saturate+0x110/0x15c [ 1946.293094] refcount_t: underflow; use-after-free. [ 1946.298164] Modules linked in: usb_f_ncm(E) u_ether(E) usb_f_fs(E) hci_uart(E) btqca(E) btrtl(E) btbcm(E) btintel(E) bluetooth(E) nls_ascii(E) nls_cp437(E) vfat(E) fat(E) bcm2835_v4l2(CE) bcm2835_mmal_vchiq(CE) videobuf2_vmalloc(E) videobuf2_memops(E) sha512_generic(E) videobuf2_v4l2(E) sha512_arm(E) videobuf2_common(E) videodev(E) cpufreq_dt(E) snd_bcm2835(CE) brcmfmac(E) mc(E) vc4(E) ctr(E) brcmutil(E) snd_soc_core(E) snd_pcm_dmaengine(E) drbg(E) snd_pcm(E) snd_timer(E) snd(E) soundcore(E) drm_kms_helper(E) cec(E) ansi_cprng(E) rc_core(E) syscopyarea(E) raspberrypi_cpufreq(E) sysfillrect(E) sysimgblt(E) cfg80211(E) max17040_battery(OE) raspberrypi_hwmon(E) fb_sys_fops(E) regmap_i2c(E) ecdh_generic(E) rfkill(E) ecc(E) bcm2835_rng(E) rng_core(E) vchiq(CE) leds_gpio(E) libcomposite(E) fuse(E) configfs(E) ip_tables(E) x_tables(E) autofs4(E) ext4(E) crc16(E) mbcache(E) jbd2(E) crc32c_generic(E) sdhci_iproc(E) sdhci_pltfm(E) sdhci(E) [ 1946.399633] CPU: 0 PID: 431 Comm: smartcard-openp Tainted: G C OE 5.15.0-1-rpi #1 Debian 5.15.3-1 [ 1946.417950] Hardware name: BCM2835 [ 1946.425442] Backtrace: [ 1946.432048] [<c08d60a0>] (dump_backtrace) from [<c08d62ec>] (show_stack+0x20/0x24) [ 1946.448226] r7:00000009 r6:0000001c r5:c04a948c r4:c0a64e2c [ 1946.458412] [<c08d62cc>] (show_stack) from [<c08d9ae0>] (dump_stack+0x28/0x30) [ 1946.470380] [<c08d9ab8>] (dump_stack) from [<c0123500>] (__warn+0xe8/0x154) [ 1946.482067] r5:c04a948c r4:c0a71dc8 [ 1946.490184] [<c0123418>] (__warn) from [<c08d6948>] (warn_slowpath_fmt+0xa0/0xe4) [ 1946.506758] r7:00000009 r6:0000001c r5:c0a71dc8 r4:c0a71e04 [ 1946.517070] [<c08d68ac>] (warn_slowpath_fmt) from [<c04a948c>] (refcount_warn_saturate+0x110/0x15c) [ 1946.535309] r8:c0100224 r7:c0dfcb84 r6:ffffffff r5:c3b84c00 r4:c24a17c0 [ 1946.546708] [<c04a937c>] (refcount_warn_saturate) from [<c0380134>] (eventfd_ctx_put+0x48/0x74) [ 1946.564476] [<c03800ec>] (eventfd_ctx_put) from [<bf5464e8>] (ffs_data_clear+0xd0/0x118 [usb_f_fs]) [ 1946.582664] r5:c3b84c00 r4:c2695b00 [ 1946.590668] [<bf546418>] (ffs_data_clear [usb_f_fs]) from [<bf547cc0>] (ffs_data_closed+0x9c/0x150 [usb_f_fs]) [ 1946.609608] r5:bf54d014 r4:c2695b00 [ 1946.617522] [<bf547c24>] (ffs_data_closed [usb_f_fs]) from [<bf547da0>] (ffs_fs_kill_sb+0x2c/0x30 [usb_f_fs]) [ 1946.636217] r7:c0dfcb84 r6:c3a12260 r5:bf54d014 r4:c229f000 [ 1946.646273] [<bf547d74>] (ffs_fs_kill_sb [usb_f_fs]) from [<c0326d50>] (deactivate_locked_super+0x54/0x9c) [ 1946.664893] r5:bf54d014 r4:c229f000 [ 1946.672921] [<c0326cfc>] (deactivate_locked_super) from [<c0326df8>] (deactivate_super+0x60/0x64) [ 1946.690722] r5:c2a09000 r4:c229f000 [ 1946.698706] [<c0326d98>] (deactivate_super) from [<c0349a28>] (cleanup_mnt+0xe4/0x14c) [ 1946.715553] r5:c2a09000 r4:00000000 [ 1946.723528] [<c0349944>] (cleanup_mnt) from [<c0349b08>] (__cleanup_mnt+0x1c/0x20) [ 1946.739922] r7:c0dfcb84 r6:c3a12260 r5:c3a126fc r4:00000000 [ 1946.750088] [<c0349aec>] (__cleanup_mnt) from [<c0143d10>] (task_work_run+0x84/0xb8) [ 1946.766602] [<c0143c8c>] (task_work_run) from [<c010bdc8>] (do_work_pending+0x470/0x56c) [ 1946.783540] r7:5ac3c35a r6:c0d0424c r5:c200bfb0 r4:c200a000 [ 1946.793614] [<c010b958>] (do_work_pending) from [<c01000c0>] (slow_work_pending+0xc/0x20) [ 1946.810553] Exception stack(0xc200bfb0 to 0xc200bff8) [ 1946.820129] bfa0: 00000000 00000000 000000aa b5e21430 [ 1946.837104] bfc0: bef867a0 00000001 bef86840 00000034 bef86838 bef86790 bef86794 bef867a0 [ 1946.854125] bfe0: 00000000 bef86798 b67b7a1c b6d626a4 60000010 b5a23760 [ 1946.865335] r10:00000000 r9:c200a000 r8:c0100224 r7:00000034 r6:bef86840 r5:00000001 [ 1946.881914] r4:bef867a0 [ 1946.888793] ---[ end trace 7387f2a9725b28d0 ]--- Fixes: 5e33f6fdf735 ("usb: gadget: ffs: add eventfd notification about ffs events") Cc: stable <stable@vger.kernel.org> Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com> Link: https://lore.kernel.org/r/f79eeea29f3f98de6782a064ec0f7351ad2f598f.1639793920.git.plr.vincent@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
ffs_data_clear is indirectly called from both ffs_fs_kill_sb and
ffs_ep0_release, so it ends up being called twice when userland closes ep0
and then unmounts f_fs.
If userland provided an eventfd along with function's USB descriptors, it
ends up calling eventfd_ctx_put as many times, causing a refcount
underflow.
NULL-ify ffs_eventfd to prevent these extraneous eventfd_ctx_put calls.

Also, set epfiles to NULL right after de-allocating it, for readability.

For completeness, ffs_data_clear actually ends up being called thrice, the
last call being before the whole ffs structure gets freed, so when this
specific sequence happens there is a second underflow happening (but not
being reported):

/sys/kernel/debug/tracing# modprobe usb_f_fs
/sys/kernel/debug/tracing# echo ffs_data_clear > set_ftrace_filter
/sys/kernel/debug/tracing# echo function > current_tracer
/sys/kernel/debug/tracing# echo 1 > tracing_on
(setup gadget, run and kill function userland process, teardown gadget)
/sys/kernel/debug/tracing# echo 0 > tracing_on
/sys/kernel/debug/tracing# cat trace
 smartcard-openp-436     [000] .....  1946.208786: ffs_data_clear <-ffs_data_closed
 smartcard-openp-431     [000] .....  1946.279147: ffs_data_clear <-ffs_data_closed
 smartcard-openp-431     [000] .n...  1946.905512: ffs_data_clear <-ffs_data_put

Warning output corresponding to above trace:
[ 1946.284139] WARNING: CPU: 0 PID: 431 at lib/refcount.c:28 refcount_warn_saturate+0x110/0x15c
[ 1946.293094] refcount_t: underflow; use-after-free.
[ 1946.298164] Modules linked in: usb_f_ncm(E) u_ether(E) usb_f_fs(E) hci_uart(E) btqca(E) btrtl(E) btbcm(E) btintel(E) bluetooth(E) nls_ascii(E) nls_cp437(E) vfat(E) fat(E) bcm2835_v4l2(CE) bcm2835_mmal_vchiq(CE) videobuf2_vmalloc(E) videobuf2_memops(E) sha512_generic(E) videobuf2_v4l2(E) sha512_arm(E) videobuf2_common(E) videodev(E) cpufreq_dt(E) snd_bcm2835(CE) brcmfmac(E) mc(E) vc4(E) ctr(E) brcmutil(E) snd_soc_core(E) snd_pcm_dmaengine(E) drbg(E) snd_pcm(E) snd_timer(E) snd(E) soundcore(E) drm_kms_helper(E) cec(E) ansi_cprng(E) rc_core(E) syscopyarea(E) raspberrypi_cpufreq(E) sysfillrect(E) sysimgblt(E) cfg80211(E) max17040_battery(OE) raspberrypi_hwmon(E) fb_sys_fops(E) regmap_i2c(E) ecdh_generic(E) rfkill(E) ecc(E) bcm2835_rng(E) rng_core(E) vchiq(CE) leds_gpio(E) libcomposite(E) fuse(E) configfs(E) ip_tables(E) x_tables(E) autofs4(E) ext4(E) crc16(E) mbcache(E) jbd2(E) crc32c_generic(E) sdhci_iproc(E) sdhci_pltfm(E) sdhci(E)
[ 1946.399633] CPU: 0 PID: 431 Comm: smartcard-openp Tainted: G         C OE     5.15.0-1-rpi #1  Debian 5.15.3-1
[ 1946.417950] Hardware name: BCM2835
[ 1946.425442] Backtrace:
[ 1946.432048] [<c08d60a0>] (dump_backtrace) from [<c08d62ec>] (show_stack+0x20/0x24)
[ 1946.448226]  r7:00000009 r6:0000001c r5:c04a948c r4:c0a64e2c
[ 1946.458412] [<c08d62cc>] (show_stack) from [<c08d9ae0>] (dump_stack+0x28/0x30)
[ 1946.470380] [<c08d9ab8>] (dump_stack) from [<c0123500>] (__warn+0xe8/0x154)
[ 1946.482067]  r5:c04a948c r4:c0a71dc8
[ 1946.490184] [<c0123418>] (__warn) from [<c08d6948>] (warn_slowpath_fmt+0xa0/0xe4)
[ 1946.506758]  r7:00000009 r6:0000001c r5:c0a71dc8 r4:c0a71e04
[ 1946.517070] [<c08d68ac>] (warn_slowpath_fmt) from [<c04a948c>] (refcount_warn_saturate+0x110/0x15c)
[ 1946.535309]  r8:c0100224 r7:c0dfcb84 r6:ffffffff r5:c3b84c00 r4:c24a17c0
[ 1946.546708] [<c04a937c>] (refcount_warn_saturate) from [<c0380134>] (eventfd_ctx_put+0x48/0x74)
[ 1946.564476] [<c03800ec>] (eventfd_ctx_put) from [<bf5464e8>] (ffs_data_clear+0xd0/0x118 [usb_f_fs])
[ 1946.582664]  r5:c3b84c00 r4:c2695b00
[ 1946.590668] [<bf546418>] (ffs_data_clear [usb_f_fs]) from [<bf547cc0>] (ffs_data_closed+0x9c/0x150 [usb_f_fs])
[ 1946.609608]  r5:bf54d014 r4:c2695b00
[ 1946.617522] [<bf547c24>] (ffs_data_closed [usb_f_fs]) from [<bf547da0>] (ffs_fs_kill_sb+0x2c/0x30 [usb_f_fs])
[ 1946.636217]  r7:c0dfcb84 r6:c3a12260 r5:bf54d014 r4:c229f000
[ 1946.646273] [<bf547d74>] (ffs_fs_kill_sb [usb_f_fs]) from [<c0326d50>] (deactivate_locked_super+0x54/0x9c)
[ 1946.664893]  r5:bf54d014 r4:c229f000
[ 1946.672921] [<c0326cfc>] (deactivate_locked_super) from [<c0326df8>] (deactivate_super+0x60/0x64)
[ 1946.690722]  r5:c2a09000 r4:c229f000
[ 1946.698706] [<c0326d98>] (deactivate_super) from [<c0349a28>] (cleanup_mnt+0xe4/0x14c)
[ 1946.715553]  r5:c2a09000 r4:00000000
[ 1946.723528] [<c0349944>] (cleanup_mnt) from [<c0349b08>] (__cleanup_mnt+0x1c/0x20)
[ 1946.739922]  r7:c0dfcb84 r6:c3a12260 r5:c3a126fc r4:00000000
[ 1946.750088] [<c0349aec>] (__cleanup_mnt) from [<c0143d10>] (task_work_run+0x84/0xb8)
[ 1946.766602] [<c0143c8c>] (task_work_run) from [<c010bdc8>] (do_work_pending+0x470/0x56c)
[ 1946.783540]  r7:5ac3c35a r6:c0d0424c r5:c200bfb0 r4:c200a000
[ 1946.793614] [<c010b958>] (do_work_pending) from [<c01000c0>] (slow_work_pending+0xc/0x20)
[ 1946.810553] Exception stack(0xc200bfb0 to 0xc200bff8)
[ 1946.820129] bfa0:                                     00000000 00000000 000000aa b5e21430
[ 1946.837104] bfc0: bef867a0 00000001 bef86840 00000034 bef86838 bef86790 bef86794 bef867a0
[ 1946.854125] bfe0: 00000000 bef86798 b67b7a1c b6d626a4 60000010 b5a23760
[ 1946.865335]  r10:00000000 r9:c200a000 r8:c0100224 r7:00000034 r6:bef86840 r5:00000001
[ 1946.881914]  r4:bef867a0
[ 1946.888793] ---[ end trace 7387f2a9725b28d0 ]---

Fixes: 5e33f6fdf735 ("usb: gadget: ffs: add eventfd notification about ffs events")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>
Link: https://lore.kernel.org/r/f79eeea29f3f98de6782a064ec0f7351ad2f598f.1639793920.git.plr.vincent@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Revert "usb: early: convert to readl_poll_timeout_atomic()" 2021-12-17T15:29:11+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2021-12-17T15:24:30+00:00 c4d936efa46d8ea183df16c0f3fa4423327da51d This reverts commit 796eed4b2342c9d6b26c958e92af91253a2390e1. This change causes boot lockups when using "arlyprintk=xdbc" because ktime can not be used at this point in time in the boot process. Also, it is not needed for very small delays like this. Reported-by: Mathias Nyman <mathias.nyman@linux.intel.com> Reported-by: Peter Zijlstra <peterz@infradead.org> Cc: Jann Horn <jannh@google.com> Cc: Chunfeng Yun <chunfeng.yun@mediatek.com> Fixes: 796eed4b2342 ("usb: early: convert to readl_poll_timeout_atomic()") Link: https://lore.kernel.org/r/c2b5c9bb-1b75-bf56-3754-b5b18812d65e@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
This reverts commit 796eed4b2342c9d6b26c958e92af91253a2390e1.

This change causes boot lockups when using "arlyprintk=xdbc" because
ktime can not be used at this point in time in the boot process.  Also,
it is not needed for very small delays like this.

Reported-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Reported-by: Peter Zijlstra <peterz@infradead.org>
Cc: Jann Horn <jannh@google.com>
Cc: Chunfeng Yun <chunfeng.yun@mediatek.com>
Fixes: 796eed4b2342 ("usb: early: convert to readl_poll_timeout_atomic()")
Link: https://lore.kernel.org/r/c2b5c9bb-1b75-bf56-3754-b5b18812d65e@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>