- 24 Jun, 2017 40 commits
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Dan Carpenter authored
commit 816c9311 upstream. This function only has one caller. Freeing "vdev" here leads to a use after free bug. There are several other error paths in this function but this is the only one which frees "vdev". It looks like the kfree() can be safely removed. Fixes: 61e9c905 ("misc: mic: Enable VOP host side functionality") Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Kalle Valo authored
commit 1427228d upstream. This fixes the below crash when ath10k probe firmware fails, NAPI polling tries to access a rx ring resource which was never allocated. An easy way to reproduce this is easy to remove all the firmware files, load ath10k modules and ath10k will crash when calling 'rmmod ath10k_pci'. The fix is to call napi_enable() from ath10k_pci_hif_start() so that it matches with napi_disable() being called from ath10k_pci_hif_stop(). Big thanks to Mohammed Shafi Shajakhan who debugged this and provided first version of the fix. In this patch I just fix the actual problem in pci.c instead of having a workaround in core.c. BUG: unable to handle kernel NULL pointer dereference at (null) IP: __ath10k_htt_rx_ring_fill_n+0x19/0x230 [ath10k_core] __ath10k_htt_rx_ring_fill_n+0x19/0x230 [ath10k_core] Call Trace: [<ffffffffa113ec62>] ath10k_htt_rx_msdu_buff_replenish+0x42/0x90 [ath10k_core] [<ffffffffa113f393>] ath10k_htt_txrx_compl_task+0x433/0x17d0 [ath10k_core] [<ffffffff8114406d>] ? __wake_up_common+0x4d/0x80 [<ffffffff811349ec>] ? cpu_load_update+0xdc/0x150 [<ffffffffa119301d>] ? ath10k_pci_read32+0xd/0x10 [ath10k_pci] [<ffffffffa1195b17>] ath10k_pci_napi_poll+0x47/0x110 [ath10k_pci] [<ffffffff817863af>] net_rx_action+0x20f/0x370 Reported-by:
Ben Greear <greearb@candelatech.com> Fixes: 3c97f5de ("ath10k: implement NAPI support") Signed-off-by:
Kalle Valo <kvalo@qca.qualcomm.com> Signed-off-by:
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Chris Brandt authored
commit dd14a3e9 upstream. The timeout for BULK packets was 300ms which is a long time if other endpoints or devices are waiting for their turn. Changing it to 50ms greatly increased the overall performance for multi-endpoint devices. Fixes: 5d304358 ("usb: r8a66597-hcd: host controller driver for R8A6659") Signed-off-by:
Chris Brandt <chris.brandt@renesas.com> Signed-off-by:
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Chris Brandt authored
commit 1f873d85 upstream. If multiple endpoints on a single device have pending IN URBs and one endpoint times out due to NAKs (perfectly legal), select a different endpoint URB to try. The existing code only checked to see another device address has pending URBs and ignores other IN endpoints on the current device address. This leads to endpoints never getting serviced if one endpoint is using NAK as a flow control method. Fixes: 5d304358 ("usb: r8a66597-hcd: host controller driver for R8A6659") Signed-off-by:
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Johan Hovold authored
commit d81182ce upstream. Flag the first and only port as removable while also leaving the remaining bits (including the reserved bit zero) unset in accordance with the specifications: "Within a byte, if no port exists for a given location, the bit field representing the port characteristics shall be 0." Also add a comment marking the legacy PortPwrCtrlMask field. Fixes: 1cd8fd28 ("usb: gadget: dummy_hcd: add SuperSpeed support") Fixes: 1da177e4 ("Linux-2.6.12-rc2") Cc: Tatyana Brokhman <tlinder@codeaurora.org> Signed-off-by:
Johan Hovold <johan@kernel.org> Acked-by:
Alan Stern <stern@rowland.harvard.edu> Signed-off-by:
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Arnd Bergmann authored
commit 6830733d upstream. The driver uses a relatively large data structure on the stack, which showed up on my radar as we get a warning with the "latent entropy" GCC plugin: drivers/media/usb/pvrusb2/pvrusb2-eeprom.c:153:1: error: the frame size of 1376 bytes is larger than 1152 bytes [-Werror=frame-larger-than=] The warning is usually hidden as we raise the warning limit to 2048 when the plugin is enabled, but I'd like to lower that again in the future, and making this function smaller helps to do that without build regressions. Further analysis shows that putting an 'i2c_client' structure on the stack is not really supported, as the embedded 'struct device' is not initialized here, and we are only saved by the fact that the function that is called here does not use the pointer at all. Fixes: d855497e ("V4L/DVB (4228a): pvrusb2 to kernel 2.6.18") Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by:
Mauro Carvalho Chehab <mchehab@s-opensource.com> Signed-off-by:
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Johan Hovold authored
commit ec963b41 upstream. Fix up the root-hub descriptor to accommodate the variable-length DeviceRemovable and PortPwrCtrlMask fields, while marking all ports as removable (and leaving the reserved bit zero unset). Also add a build-time constraint on VHCI_HC_PORTS which must never be greater than USB_MAXCHILDREN (but this was only enforced through a KConfig constant). This specifically fixes the descriptor layout whenever VHCI_HC_PORTS is greater than seven (default is 8). Fixes: 04679b34 ("Staging: USB/IP: add client driver") Cc: Takahiro Hirofuchi <hirofuchi@users.sourceforge.net> Cc: Valentina Manea <valentina.manea.m@gmail.com> Signed-off-by:
Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by:
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Anton Bondarenko authored
commit 1a744d2e upstream. Free memory allocated for address0_mutex if allocation of bandwidth_mutex failed. Fixes: feb26ac3 ("usb: core: hub: hub_port_init lock controller instead of bus") Signed-off-by:
Anton Bondarenko <anton.bondarenko.sama@gmail.com> Acked-by:
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Johan Hovold authored
commit 93491ced upstream. Add define for the maximum number of ports on a SuperSpeed hub as per USB 3.1 spec Table 10-5, and use it when verifying the retrieved hub descriptor. This specifically avoids benign attempts to update the DeviceRemovable mask for non-existing ports (should we get that far). Fixes: dbe79bbe ("USB 3.0 Hub Changes") Acked-by:
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Yoshihiro Shimoda authored
commit 940f538a upstream. This controller disallows to change the PIPE until reading/writing a packet finishes. However. the previous code is not enough to hold the lock in some functions. So, this patch fixes it. Fixes: 746bfe63 ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller") Signed-off-by:
Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by:
Felipe Balbi <felipe.balbi@linux.intel.com> Signed-off-by:
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Yoshihiro Shimoda authored
commit 067d6fdc upstream. This patch fixes an issue that this driver is possible to cause deadlock by double-spinclocked in renesas_usb3_stop_controller(). So, this patch removes spinlock API calling in renesas_usb3_stop(). (In other words, the previous code had a redundant lock.) Fixes: 746bfe63 ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller") Signed-off-by:
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Yoshihiro Shimoda authored
commit cdc87687 upstream. This patch fixes an issue that this driver is possible to access the registers before pm_runtime_get_sync() if a gadget driver is installed first. After that, oops happens on R-Car Gen3 environment. To avoid it, this patch changes the pm_runtime call timing from probe/remove to udc_start/udc_stop. Fixes: 746bfe63 ("usb: gadget: renesas_usb3: add support for Renesas USB3.0 peripheral controller") Signed-off-by:
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Eli Cohen authored
commit de8d6e02 upstream. The logic was broken as it failed to update the response length for architectures with PAGE_SIZE larger than 4kB. As a result further extension of the ucontext response struct would fail. Fixes: d69e3bcf ('IB/mlx5: Mmap the HCA's core clock register to user-space') Signed-off-by:
Eli Cohen <eli@mellanox.com> Reviewed-by:
Matan Barak <matanb@mellanox.com> Signed-off-by:
Leon Romanovsky <leon@kernel.org> Signed-off-by:
Saeed Mahameed <saeedm@mellanox.com> Signed-off-by:
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Dan Carpenter authored
commit 5ba5b437 upstream. We should be allocating enough information for a tiadc_device struct which is about 400 bytes but instead we allocate enough for a second iio_dev struct which is over 2000 bytes. Fixes: fea89e2d ("iio: adc: ti_am335x_adc: use variable names for sizeof() operator") Signed-off-by:
Jonathan Cameron <jic23@kernel.org> Signed-off-by:
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Matt Ranostay authored
commit 6272c0de upstream. According to the datasheet the RCO must be recalibrated on every power-on-reset. Also remove mutex locking in the calibration function since callers other than the probe function (which doesn't need it) will have a lock. Fixes: 24ddb0e4 ("iio: Add AS3935 lightning sensor support") Cc: George McCollister <george.mccollister@gmail.com> Signed-off-by:
Matt Ranostay <matt.ranostay@konsulko.com> Signed-off-by:
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Marcin Niestroj authored
commit 1b211d48 upstream. Datasheet of each device (lps331ap, lps25h, lps001wp, lps22hb) says that the pressure and temperature data is a 2's complement. I'm sending this the slow way, as negative pressures on these are pretty unusual and the nature of the fixing of multiple device introduction patches will make it hard to apply to older kernels - Jonathan. Fixes: 217494e5 ("iio:pressure: Add STMicroelectronics pressures driver") Fixes: 2f5effcb ("iio: pressure-core: st: Expand and rename LPS331AP's channel descriptor") Fixes: 7885a8ce ("iio: pressure: st: Add support for new LPS001WP pressure sensor") Fixes: e039e2f5 ("iio:st_pressure:initial lps22hb sensor support") Signed-off-by:
Marcin Niestroj <m.niestroj@grinn-global.com> Reviewed-by:
Linus Walleij <linus.walleij@linaro.org> Signed-off-by:
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Eva Rachel Retuya authored
commit cf6c7732 upstream. Standard deviation is calculated as the square root of the variance where variance is the mean of sample_sum and length. Correct the computation of statP->stddev in accordance to the proper calculation. Fixes: 3c97c08b ("staging: iio: add TAOS tsl2x7x driver") Reported-by:
Abhiram Balasubramanian <abhiram@cs.utah.edu> Signed-off-by:
Eva Rachel Retuya <eraretuya@gmail.com> Signed-off-by:
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Dan Carpenter authored
commit 784047eb upstream. The "len" could be as low as -14 so we should check for negatives. Fixes: 9a7fe54d ("staging: r8188eu: Add source files for new driver - part 1") Signed-off-by:
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Tony Lindgren authored
commit 8b8a84c5 upstream. Commit 16fa3dc7 ("mfd: omap-usb-tll: HOST TLL platform driver") added support for USB TLL, but uses OMAP_TLL_CHANNEL_CONF_ULPINOBITSTUFF bit the wrong way. The comments in the code are correct, but the inverted use of OMAP_TLL_CHANNEL_CONF_ULPINOBITSTUFF causes the register to be enabled instead of disabled unlike what the comments say. Without this change the Wrigley 3G LTE modem on droid 4 EHCI bus can be only pinged few times before it stops responding. Fixes: 16fa3dc7 ("mfd: omap-usb-tll: HOST TLL platform driver") Signed-off-by:
Tony Lindgren <tony@atomide.com> Acked-by:
Roger Quadros <rogerq@ti.com> Signed-off-by:
Lee Jones <lee.jones@linaro.org> Signed-off-by:
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Laura Abbott authored
commit 861ce4a3 upstream. '__vmalloc_start_set' currently only gets set in initmem_init() when !CONFIG_NEED_MULTIPLE_NODES. This breaks detection of vmalloc address with virt_addr_valid() with CONFIG_NEED_MULTIPLE_NODES=y, causing a kernel crash: [mm/usercopy] 517e1fbe: kernel BUG at arch/x86/mm/physaddr.c:78! Set '__vmalloc_start_set' appropriately for that case as well. Reported-by:
kbuild test robot <fengguang.wu@intel.com> Signed-off-by:
Laura Abbott <labbott@redhat.com> Reviewed-by:
Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: dc16ecf7 ("x86-32: use specific __vmalloc_start_set flag in __virt_addr_valid") Link: http://lkml.kernel.org/r/1494278596-30373-1-git-send-email-labbott@redhat.comSigned-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
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Geert Uytterhoeven authored
commit 5f76895e upstream. When changing hardware control flow for a UART with dedicated RTS/CTS pins, the new AUTORTS state is not immediately reflected in the hardware, but only when RTS is raised. However, the serial core does not call .set_mctrl() after .set_termios(), hence AUTORTS may only become effective when the port is closed, and reopened later. Note that this problem does not happen when manually using stty to change CRTSCTS, as AUTORTS will work fine on next open. To fix this, call .set_mctrl() from .set_termios() when dedicated RTS/CTS pins are present, to refresh the AUTORTS or RTS state. This is similar to what other drivers supporting AUTORTS do (e.g. omap-serial). Reported-by:
Baumann, Christoph (C.) <cbaumann@visteon.com> Fixes: 33f50ffc ("serial: sh-sci: Fix support for hardware-assisted RTS/CTS") Signed-off-by:
Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by:
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Christophe JAILLET authored
commit be40597a upstream. UARTn_FRAME_PARITY_ODD is 0x0300 UARTn_FRAME_PARITY_EVEN is 0x0200 So if the UART is configured for EVEN parity, it would be reported as ODD. Fix it by correctly testing if the 2 bits are set. Fixes: 3afbd89c ("serial/efm32: add new driver") Signed-off-by:
Christophe JAILLET <christophe.jaillet@wanadoo.fr> Acked-by:
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by:
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Eric Anholt authored
commit ca39b449 upstream. If a CMA allocation failed, the partially constructed BO would be unreferenced through the normal path, and we might choose to put it in the BO cache. If we then reused it before it expired from the cache, the kernel would OOPS. Signed-off-by:
Eric Anholt <eric@anholt.net> Fixes: c826a6e1 ("drm/vc4: Add a BO cache.") Reviewed-by:
Boris Brezillon <boris.brezillon@free-electrons.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170301185602.6873-2-eric@anholt.netSigned-off-by:
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YYS authored
commit 014580ff upstream. mtk_hdmi_setup_vendor_specific_infoframe will return before handle mtk_hdmi_hw_send_info_frame.Because hdmi_vendor_infoframe_pack returns the number of bytes packed into the binary buffer or a negative error code on failure. So correct it. Fixes: 8f83f268 ("drm/mediatek: Add HDMI support") Signed-off-by:
Nickey Yang <nickey.yang@rock-chips.com> Signed-off-by:
CK Hu <ck.hu@mediatek.com> Signed-off-by:
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Emmanuel Grumbach authored
commit b3dd8279 upstream. mac80211 allows to modify the SMPS state of an AP both, when it is started, and after it has been started. Such a change will trigger an action frame to all the peers that are currently connected, and will be remembered so that new peers will get notified as soon as they connect (since the SMPS setting in the beacon may not be the right one). This means that we need to remember the SMPS state currently requested as well as the SMPS state that was configured initially (and advertised in the beacon). The former is bss->req_smps and the latter is sdata->smps_mode. Initially, the AP interface could only be started with SMPS_OFF, which means that sdata->smps_mode was SMPS_OFF always. Later, a nl80211 API was added to be able to start an AP with a different AP mode. That code forgot to update bss->req_smps and because of that, if the AP interface was started with SMPS_DYNAMIC, we had: sdata->smps_mode = SMPS_DYNAMIC bss->req_smps = SMPS_OFF That configuration made mac80211 think it needs to fire off an action frame to any new station connecting to the AP in order to let it know that the actual SMPS configuration is SMPS_OFF. Fix that by properly setting bss->req_smps in ieee80211_start_ap. Fixes: f6993174 ("mac80211: set smps_mode according to ap params") Signed-off-by:
Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by:
Luca Coelho <luciano.coelho@intel.com> Signed-off-by:
Johannes Berg <johannes.berg@intel.com> Signed-off-by:
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Johannes Berg authored
commit e165bc02 upstream. In the commit enabling per-CPU station statistics, I inadvertedly copy-pasted some code to update rx_packets and forgot to change it to update rx_dropped_misc. Fix that. This addresses https://bugzilla.kernel.org/show_bug.cgi?id=195953. Fixes: c9c5962b ("mac80211: enable collecting station statistics per-CPU") Reported-by:
Petru-Florin Mihancea <petrum@gmail.com> Signed-off-by:
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Rajkumar Manoharan authored
commit 5667c86a upstream. Mesh forwarding path checks for address extension mode to fetch appropriate proxied address and MPP address. Existing condition that looks for 6 address format is not strict enough so that frames with improper values are processed and invalid entries are added into MPP table. Fix that by adding a stricter check before processing the packet. Per IEEE Std 802.11s-2011 spec. Table 7-6g1 lists address extension mode 0x3 as reserved one. And also Table Table 9-13 does not specify 0x3 as valid address field. Fixes: 9b395bc3 ("mac80211: verify that skb data is present") Signed-off-by:
Rajkumar Manoharan <rmanohar@qti.qualcomm.com> Signed-off-by:
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Johannes Berg authored
commit f1f3e9e2 upstream. When VHT IBSS support was added, the size of the extra elements wasn't considered in ieee80211_ibss_build_presp(), which makes it possible that it would overrun the allocated buffer. Fix it by allocating the necessary space. Fixes: abcff6ef ("mac80211: add VHT support for IBSS") Reported-by:
Shaul Triebitz <shaul.triebitz@intel.com> Signed-off-by:
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Johannes Berg authored
commit 0328edc7 upstream. When adding per-CPU statistics, which added statistics back to mac80211 for the fast-RX path, I evidently forgot to add the "stats->packets++" line. The reason for that is likely that I didn't see it since it's done in defragmentation for the regular RX path. Add the missing line to properly count received packets in the fast-RX case. Fixes: c9c5962b ("mac80211: enable collecting station statistics per-CPU") Reported-by:
Oren Givon <oren.givon@intel.com> Signed-off-by:
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Koen Vandeputte authored
commit f181d6a3 upstream. Add the missing IBSS capability flag during capability init as it needs to be inserted into the generated beacon in order for CSA to work. Fixes: cd7760e6 ("mac80211: add support for CSA in IBSS mode") Signed-off-by:
Piotr Gawlowicz <gawlowicz@tkn.tu-berlin.de> Signed-off-by:
Mikołaj Chwalisz <chwalisz@tkn.tu-berlin.de> Tested-by:
Koen Vandeputte <koen.vandeputte@ncentric.com> Signed-off-by:
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Bin Liu authored
commit b3addcf0 upstream. Currently VBUS is turned off while a usb device is detached, and turned on again by the polling routine. This short period VBUS loss prevents usb modem to switch mode. VBUS should be constantly on for host-only mode, so this changes the driver to not turn off VBUS for host-only mode. Fixes: 2f3fd2c5 ("usb: musb: Prepare dsps glue layer for PM runtime support") Reported-by:
Moreno Bartalucci <moreno.bartalucci@tecnorama.it> Acked-by:
Bin Liu <b-liu@ti.com> Signed-off-by:
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Zhenyu Wang authored
commit c380f681 upstream. Current it's strictly checked if PVINFO version matches 1.0 for GVT-g i915 guest which doesn't help for compatibility at all and forces GVT-g host can't extend PVINFO easily with version bump for real compatibility check. This fixes that to check minimal required PVINFO version instead. v2: - drop unneeded version macro - use only major version for sanity check v3: - fix up PVInfo value with kernel type - one indent fix Reviewed-by:
Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Chuanxiao Dong <chuanxiao.dong@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Signed-off-by:
Zhenyu Wang <zhenyuw@linux.intel.com> Signed-off-by:
Jani Nikula <jani.nikula@intel.com> Signed-off-by:
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Mario Kleiner authored
commit bea10413 upstream. Commit d63c277d ("drm/amdgpu: Make display watermark calculations more accurate") made watermark calculations more accurate, but not for > 4k resolutions on 32-Bit architectures, as it introduced an integer overflow for those setups and resolutions. Fix this by proper u64 casting and division. Signed-off-by:
Mario Kleiner <mario.kleiner.de@gmail.com> Reported-by:
Ben Hutchings <ben.hutchings@codethink.co.uk> Fixes: d63c277d ("drm/amdgpu: Make display watermark calculations more accurate") Cc: Ben Hutchings <ben.hutchings@codethink.co.uk> Cc: Alex Deucher <alexander.deucher@amd.com> Signed-off-by:
Alex Deucher <alexander.deucher@amd.com> Signed-off-by:
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Jason A. Donenfeld authored
commit 98c67d18 upstream. Otherwise, we enable all sorts of forgeries via timing attack. Signed-off-by:
Jason A. Donenfeld <Jason@zx2c4.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: linux-wireless@vger.kernel.org Signed-off-by:
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Emmanuel Grumbach authored
commit 769dc04d upstream. When a peer sends a BAR frame with PM bit clear, we should not modify its PM state as madated by the spec in 802.11-20012 10.2.1.2. Signed-off-by:
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Christophe JAILLET authored
commit 5ebb6dd3 upstream. We should ensure that 'plane_no' is '< vb->num_planes' as done in 'vb2_plane_cookie' just a few lines below. Fixes: e23ccc0a ("[media] v4l: add videobuf2 Video for Linux 2 driver framework") Signed-off-by:
Sakari Ailus <sakari.ailus@linux.intel.com> Signed-off-by:
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Tomasz Wilczyński authored
commit b8e11f7d upstream. Commit 27ed3cd2 (cpufreq: conservative: Fix the logic in frequency decrease checking) removed the 10 point substraction when comparing the load against down_threshold but did not remove the related limit for the down_threshold value. As a result, down_threshold lower than 11 is not allowed even though values from 1 to 10 do work correctly too. The comment ("cannot be lower than 11 otherwise freq will not fall") also does not apply after removing the substraction. For this reason, allow down_threshold to take any value from 1 to 99 and fix the related comment. Fixes: 27ed3cd2 (cpufreq: conservative: Fix the logic in frequency decrease checking) Signed-off-by:
Tomasz Wilczyński <twilczynski@naver.com> Acked-by:
Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by:
Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by:
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Arnd Bergmann authored
commit 0db47e3d upstream. While discussing the possible merits of clang warning about unused initialized functions, I found one function that was clearly meant to be called but never actually is. __ila_hash_secret_init() initializes the hash value for the ila locator, apparently this is intended to prevent hash collision attacks, but this ends up being a read-only zero constant since there is no caller. I could find no indication of why it was never called, the earliest patch submission for the module already was like this. If my interpretation is right, we certainly want to backport the patch to stable kernels as well. I considered adding it to the ila_xlat_init callback, but for best effect the random data is read as late as possible, just before it is first used. The underlying net_get_random_once() is already highly optimized to avoid overhead when called frequently. Fixes: 7f00feaf ("ila: Add generic ILA translation facility") Link: https://www.spinics.net/lists/kernel/msg2527243.htmlSigned-off-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
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Marc Kleine-Budde authored
commit 5cda3ee5 upstream. This patch adds the missing kfree() in gs_cmd_reset() to free the memory that is not used anymore after usb_control_msg(). Cc: Maximilian Schneider <max@schneidersoft.net> Signed-off-by:
Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by:
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Nicholas Bellinger authored
commit ba80aa90 upstream. This patch closes a long standing race in configfs between the creation of a new symlink in create_link(), while the symlink target's config_item is being concurrently removed via configfs_rmdir(). This can happen because the symlink target's reference is obtained by config_item_get() in create_link() before the CONFIGFS_USET_DROPPING bit set by configfs_detach_prep() during configfs_rmdir() shutdown is actually checked.. This originally manifested itself on ppc64 on v4.8.y under heavy load using ibmvscsi target ports with Novalink API: [ 7877.289863] rpadlpar_io: slot U8247.22L.212A91A-V1-C8 added [ 7879.893760] ------------[ cut here ]------------ [ 7879.893768] WARNING: CPU: 15 PID: 17585 at ./include/linux/kref.h:46 config_item_get+0x7c/0x90 [configfs] [ 7879.893811] CPU: 15 PID: 17585 Comm: targetcli Tainted: G O 4.8.17-customv2.22 #12 [ 7879.893812] task: c00000018a0d3400 task.stack: c0000001f3b40000 [ 7879.893813] NIP: d000000002c664ec LR: d000000002c60980 CTR: c000000000b70870 [ 7879.893814] REGS: c0000001f3b43810 TRAP: 0700 Tainted: G O (4.8.17-customv2.22) [ 7879.893815] MSR: 8000000000029033 <SF,EE,ME,IR,DR,RI,LE> CR: 28222242 XER: 00000000 [ 7879.893820] CFAR: d000000002c664bc SOFTE: 1 GPR00: d000000002c60980 c0000001f3b43a90 d000000002c70908 c0000000fbc06820 GPR04: c0000001ef1bd900 0000000000000004 0000000000000001 0000000000000000 GPR08: 0000000000000000 0000000000000001 d000000002c69560 d000000002c66d80 GPR12: c000000000b70870 c00000000e798700 c0000001f3b43ca0 c0000001d4949d40 GPR16: c00000014637e1c0 0000000000000000 0000000000000000 c0000000f2392940 GPR20: c0000001f3b43b98 0000000000000041 0000000000600000 0000000000000000 GPR24: fffffffffffff000 0000000000000000 d000000002c60be0 c0000001f1dac490 GPR28: 0000000000000004 0000000000000000 c0000001ef1bd900 c0000000f2392940 [ 7879.893839] NIP [d000000002c664ec] config_item_get+0x7c/0x90 [configfs] [ 7879.893841] LR [d000000002c60980] check_perm+0x80/0x2e0 [configfs] [ 7879.893842] Call Trace: [ 7879.893844] [c0000001f3b43ac0] [d000000002c60980] check_perm+0x80/0x2e0 [configfs] [ 7879.893847] [c0000001f3b43b10] [c000000000329770] do_dentry_open+0x2c0/0x460 [ 7879.893849] [c0000001f3b43b70] [c000000000344480] path_openat+0x210/0x1490 [ 7879.893851] [c0000001f3b43c80] [c00000000034708c] do_filp_open+0xfc/0x170 [ 7879.893853] [c0000001f3b43db0] [c00000000032b5bc] do_sys_open+0x1cc/0x390 [ 7879.893856] [c0000001f3b43e30] [c000000000009584] system_call+0x38/0xec [ 7879.893856] Instruction dump: [ 7879.893858] 409d0014 38210030 e8010010 7c0803a6 4e800020 3d220000 e94981e0 892a0000 [ 7879.893861] 2f890000 409effe0 39200001 992a0000 <0fe00000> 4bffffd0 60000000 60000000 [ 7879.893866] ---[ end trace 14078f0b3b5ad0aa ]--- To close this race, go ahead and obtain the symlink's target config_item reference only after the existing CONFIGFS_USET_DROPPING check succeeds. This way, if configfs_rmdir() wins create_link() will return -ENONET, and if create_link() wins configfs_rmdir() will return -EBUSY. Reported-by:
Bryant G. Ly <bryantly@linux.vnet.ibm.com> Tested-by:
Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
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