user/sven/linux.git/Documentation, branch v4.9.261

sysfs: Add sysfs_emit and sysfs_emit_at to format sysfs output

2021-03-07T10:25:58Z

commit 2efc459d06f1630001e3984854848a5647086232 upstream. Output defects can exist in sysfs content using sprintf and snprintf. sprintf does not know the PAGE_SIZE maximum of the temporary buffer used for outputting sysfs content and it's possible to overrun the PAGE_SIZE buffer length. Add a generic sysfs_emit function that knows that the size of the temporary buffer and ensures that no overrun is done. Add a generic sysfs_emit_at function that can be used in multiple call situations that also ensures that no overrun is done. Validate the output buffer argument to be page aligned. Validate the offset len argument to be within the PAGE_SIZE buf. Signed-off-by: Joe Perches Link: https://lore.kernel.org/r/884235202216d464d61ee975f7465332c86f76b2.1600285923.git.joe@perches.com Signed-off-by: Greg Kroah-Hartman

dt-bindings: net: correct interrupt flags in examples

2020-12-11T12:37:58Z

[ Upstream commit 4d521943f76bd0d1e68ea5e02df7aadd30b2838a ] GPIO_ACTIVE_x flags are not correct in the context of interrupt flags. These are simple defines so they could be used in DTS but they will not have the same meaning: 1. GPIO_ACTIVE_HIGH = 0 = IRQ_TYPE_NONE 2. GPIO_ACTIVE_LOW = 1 = IRQ_TYPE_EDGE_RISING Correct the interrupt flags, assuming the author of the code wanted same logical behavior behind the name "ACTIVE_xxx", this is: ACTIVE_LOW => IRQ_TYPE_LEVEL_LOW ACTIVE_HIGH => IRQ_TYPE_LEVEL_HIGH Fixes: a1a8b4594f8d ("NFC: pn544: i2c: Add DTS Documentation") Fixes: 6be88670fc59 ("NFC: nxp-nci_i2c: Add I2C support to NXP NCI driver") Fixes: e3b329221567 ("dt-bindings: can: tcan4x5x: Update binding to use interrupt property") Signed-off-by: Krzysztof Kozlowski Acked-by: Rob Herring Acked-by: Marc Kleine-Budde # for tcan4x5x.txt Link: https://lore.kernel.org/r/20201026153620.89268-1-krzk@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

powerpc/64s: flush L1D after user accesses

2020-11-22T08:58:14Z

commit 9a32a7e78bd0cd9a9b6332cbdc345ee5ffd0c5de upstream. IBM Power9 processors can speculatively operate on data in the L1 cache before it has been completely validated, via a way-prediction mechanism. It is not possible for an attacker to determine the contents of impermissible memory using this method, since these systems implement a combination of hardware and software security measures to prevent scenarios where protected data could be leaked. However these measures don't address the scenario where an attacker induces the operating system to speculatively execute instructions using data that the attacker controls. This can be used for example to speculatively bypass "kernel user access prevention" techniques, as discovered by Anthony Steinhauser of Google's Safeside Project. This is not an attack by itself, but there is a possibility it could be used in conjunction with side-channels or other weaknesses in the privileged code to construct an attack. This issue can be mitigated by flushing the L1 cache between privilege boundaries of concern. This patch flushes the L1 cache after user accesses. This is part of the fix for CVE-2020-4788. Signed-off-by: Nicholas Piggin Signed-off-by: Daniel Axtens Signed-off-by: Greg Kroah-Hartman

powerpc/64s: flush L1D on kernel entry

2020-11-22T08:58:13Z

commit f79643787e0a0762d2409b7b8334e83f22d85695 upstream. IBM Power9 processors can speculatively operate on data in the L1 cache before it has been completely validated, via a way-prediction mechanism. It is not possible for an attacker to determine the contents of impermissible memory using this method, since these systems implement a combination of hardware and software security measures to prevent scenarios where protected data could be leaked. However these measures don't address the scenario where an attacker induces the operating system to speculatively execute instructions using data that the attacker controls. This can be used for example to speculatively bypass "kernel user access prevention" techniques, as discovered by Anthony Steinhauser of Google's Safeside Project. This is not an attack by itself, but there is a possibility it could be used in conjunction with side-channels or other weaknesses in the privileged code to construct an attack. This issue can be mitigated by flushing the L1 cache between privilege boundaries of concern. This patch flushes the L1 cache on kernel entry. This is part of the fix for CVE-2020-4788. Signed-off-by: Nicholas Piggin Signed-off-by: Daniel Axtens Signed-off-by: Greg Kroah-Hartman

xen/events: defer eoi in case of excessive number of events

2020-11-18T17:26:31Z

commit e99502f76271d6bc4e374fe368c50c67a1fd3070 upstream. In case rogue guests are sending events at high frequency it might happen that xen_evtchn_do_upcall() won't stop processing events in dom0. As this is done in irq handling a crash might be the result. In order to avoid that, delay further inter-domain events after some time in xen_evtchn_do_upcall() by forcing eoi processing into a worker on the same cpu, thus inhibiting new events coming in. The time after which eoi processing is to be delayed is configurable via a new module parameter "event_loop_timeout" which specifies the maximum event loop time in jiffies (default: 2, the value was chosen after some tests showing that a value of 2 was the lowest with an only slight drop of dom0 network throughput while multiple guests performed an event storm). How long eoi processing will be delayed can be specified via another parameter "event_eoi_delay" (again in jiffies, default 10, again the value was chosen after testing with different delay values). This is part of XSA-332. Cc: stable@vger.kernel.org Reported-by: Julien Grall Signed-off-by: Juergen Gross Reviewed-by: Stefano Stabellini Reviewed-by: Wei Liu Signed-off-by: Greg Kroah-Hartman

icmp: randomize the global rate limiter

2020-10-29T08:05:32Z

[ Upstream commit b38e7819cae946e2edf869e604af1e65a5d241c5 ] Keyu Man reported that the ICMP rate limiter could be used by attackers to get useful signal. Details will be provided in an upcoming academic publication. Our solution is to add some noise, so that the attackers no longer can get help from the predictable token bucket limiter. Fixes: 4cdf507d5452 ("icmp: add a global rate limitation") Signed-off-by: Eric Dumazet Reported-by: Keyu Man Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

ata: make qc_prep return ata_completion_errors

2020-10-01T18:40:19Z

commit 95364f36701e62dd50eee91e1303187fd1a9f567 upstream. In case a driver wants to return an error from qc_prep, return enum ata_completion_errors. sata_mv is one of those drivers -- see the next patch. Other drivers return the newly defined AC_ERR_OK. [v2] use enum ata_completion_errors and AC_ERR_OK. Signed-off-by: Jiri Slaby Cc: Jens Axboe Cc: linux-ide@vger.kernel.org Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

dt-bindings: sound: wm8994: Correct required supplies based on actual implementaion

2020-10-01T18:40:12Z

[ Upstream commit 8c149b7d75e53be47648742f40fc90d9fc6fa63a ] The required supplies in bindings were actually not matching implementation making the bindings incorrect and misleading. The Linux kernel driver requires all supplies to be present. Also for wlf,wm8994 uses just DBVDD-supply instead of DBVDDn-supply (n: <1,3>). Reported-by: Jonathan Bakker Signed-off-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20200501133534.6706-1-krzk@kernel.org Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

affs: fix basic permission bits to actually work

2020-09-12T09:47:39Z

[ Upstream commit d3a84a8d0dde4e26bc084b36ffcbdc5932ac85e2 ] The basic permission bits (protection bits in AmigaOS) have been broken in Linux' AFFS - it would only set bits, but never delete them. Also, contrary to the documentation, the Archived bit was not handled. Let's fix this for good, and set the bits such that Linux and classic AmigaOS can coexist in the most peaceful manner. Also, update the documentation to represent the current state of things. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Max Staudt Signed-off-by: David Sterba Signed-off-by: Sasha Levin

iio: improve IIO_CONCENTRATION channel type description

2020-08-21T09:02:00Z

[ Upstream commit df16c33a4028159d1ba8a7061c9fa950b58d1a61 ] IIO_CONCENTRATION together with INFO_RAW specifier is used for reporting raw concentrations of pollutants. Raw value should be meaningless before being properly scaled. Because of that description shouldn't mention raw value unit whatsoever. Fix this by rephrasing existing description so it follows conventions used throughout IIO ABI docs. Fixes: 8ff6b3bc94930 ("iio: chemical: Add IIO_CONCENTRATION channel type") Signed-off-by: Tomasz Duszynski Acked-by: Matt Ranostay Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin