- 20 Oct, 2018 9 commits
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Sven Eckelmann authored
[ Upstream commit ae3cdc97 ] The function batadv_tvlv_handler_register is responsible for adding new tvlv_handler to the handler_list. It first checks whether the entry already is in the list or not. If it is, then the creation of a new entry is aborted. But the lock for the list is only held when the list is really modified. This could lead to duplicated entries because another context could create an entry with the same key between the check and the list manipulation. The check and the manipulation of the list must therefore be in the same locked code section. Fixes: ef261577 ("batman-adv: tvlv - basic infrastructure") Signed-off-by:
Sven Eckelmann <sven@narfation.org> Signed-off-by:
Simon Wunderlich <sw@simonwunderlich.de> Signed-off-by:
Sasha Levin <alexander.levin@microsoft.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Sven Eckelmann authored
[ Upstream commit e7136e48 ] The function batadv_tt_global_orig_entry_add is responsible for adding new tt_orig_list_entry to the orig_list. It first checks whether the entry already is in the list or not. If it is, then the creation of a new entry is aborted. But the lock for the list is only held when the list is really modified. This could lead to duplicated entries because another context could create an entry with the same key between the check and the list manipulation. The check and the manipulation of the list must therefore be in the same locked code section. Fixes: d657e621 ("batman-adv: add reference counting for type batadv_tt_orig_list_entry") Signed-off-by:
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Sven Eckelmann authored
[ Upstream commit 94cb82f5 ] The function batadv_softif_vlan_get is responsible for adding new softif_vlan to the softif_vlan_list. It first checks whether the entry already is in the list or not. If it is, then the creation of a new entry is aborted. But the lock for the list is only held when the list is really modified. This could lead to duplicated entries because another context could create an entry with the same key between the check and the list manipulation. The check and the manipulation of the list must therefore be in the same locked code section. Fixes: 5d2c05b2 ("batman-adv: add per VLAN interface attribute framework") Signed-off-by:
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Sven Eckelmann authored
[ Upstream commit fa122fec ] The function batadv_nc_get_nc_node is responsible for adding new nc_nodes to the in_coding_list and out_coding_list. It first checks whether the entry already is in the list or not. If it is, then the creation of a new entry is aborted. But the lock for the list is only held when the list is really modified. This could lead to duplicated entries because another context could create an entry with the same key between the check and the list manipulation. The check and the manipulation of the list must therefore be in the same locked code section. Fixes: d56b1705 ("batman-adv: network coding - detect coding nodes and remove these after timeout") Signed-off-by:
Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by:
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Sven Eckelmann authored
[ Upstream commit dff9bc42 ] The function batadv_gw_node_add is responsible for adding new gw_node to the gateway_list. It is expecting that the caller already checked that there is not already an entry with the same key or not. But the lock for the list is only held when the list is really modified. This could lead to duplicated entries because another context could create an entry with the same key between the check and the list manipulation. The check and the manipulation of the list must therefore be in the same locked code section. Fixes: c6c8fea2 ("net: Add batman-adv meshing protocol") Signed-off-by:
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Sven Eckelmann authored
[ Upstream commit a25bab9d ] The per hardif sysfs file "batman_adv/elp_interval" is using the generic functions to store/show uint values. The helper __batadv_store_uint_attr requires the softif net_device as parameter to print the resulting change as info text when the users writes to this file. It uses the helper function batadv_info to add it at the same time to the kernel ring buffer and to the batman-adv debug log (when CONFIG_BATMAN_ADV_DEBUG is enabled). The function batadv_info requires as first parameter the batman-adv softif net_device. This parameter is then used to find the private buffer which contains the debug log for this batman-adv interface. But batadv_store_throughput_override used as first argument the slave net_device. This slave device doesn't have the batadv_priv private data which is access by batadv_info. Writing to this file with CONFIG_BATMAN_ADV_DEBUG enabled can either lead to a segfault or to memory corruption. Fixes: 0744ff8f ("batman-adv: Add hard_iface specific sysfs wrapper macros for UINT") Signed-off-by:
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Sven Eckelmann authored
[ Upstream commit b9fd14c2 ] The per hardif sysfs file "batman_adv/throughput_override" prints the resulting change as info text when the users writes to this file. It uses the helper function batadv_info to add it at the same time to the kernel ring buffer and to the batman-adv debug log (when CONFIG_BATMAN_ADV_DEBUG is enabled). The function batadv_info requires as first parameter the batman-adv softif net_device. This parameter is then used to find the private buffer which contains the debug log for this batman-adv interface. But batadv_store_throughput_override used as first argument the slave net_device. This slave device doesn't have the batadv_priv private data which is access by batadv_info. Writing to this file with CONFIG_BATMAN_ADV_DEBUG enabled can either lead to a segfault or to memory corruption. Fixes: 0b5ecc68 ("batman-adv: add throughput override attribute to hard_ifaces") Signed-off-by:
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Sven Eckelmann authored
[ Upstream commit 88d0895d ] The probe ELPs for WiFi interfaces are expanded to contain at least BATADV_ELP_MIN_PROBE_SIZE bytes. This is usually a lot more than the number of bytes which the template ELP packet requires. These extra padding bytes were not initialized and thus could contain data which were previously stored at the same location. It is therefore required to set it to some predefined or random values to avoid leaking private information from the system transmitting these kind of packets. Fixes: e4623c913508 ("batman-adv: Avoid probe ELP information leak") Signed-off-by:
Antonio Quartulli <a@unstable.cc> Signed-off-by:
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Jozef Balga authored
[ Upstream commit 312f73b6 ] When less than 3 bytes are written to the device, memcpy is called with negative array size which leads to buffer overflow and kernel panic. This patch adds a condition and returns -EOPNOTSUPP instead. Fixes bugzilla issue 64871 [mchehab+samsung@kernel.org: fix a merge conflict and changed the condition to match the patch's comment, e. g. len == 3 could also be valid] Signed-off-by:
Jozef Balga <jozef.balga@gmail.com> Signed-off-by:
Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Signed-off-by:
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- 18 Oct, 2018 31 commits
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Greg Kroah-Hartman authored
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Jiri Olsa authored
commit 77f18153 upstream. With gcc 8 we get new set of snprintf() warnings that breaks the compilation, one example: tests/mem.c: In function ‘check’: tests/mem.c:19:48: error: ‘%s’ directive output may be truncated writing \ up to 99 bytes into a region of size 89 [-Werror=format-truncation=] snprintf(failure, sizeof failure, "unexpected %s", out); The gcc docs says: To avoid the warning either use a bigger buffer or handle the function's return value which indicates whether or not its output has been truncated. Given that all these warnings are harmless, because the code either properly fails due to uncomplete file path or we don't care for truncated output at all, I'm changing all those snprintf() calls to scnprintf(), which actually 'checks' for the snprint return value so the gcc stays silent. Signed-off-by:
Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Link: http://lkml.kernel.org/r/20180319082902.4518-1-jolsa@kernel.orgSigned-off-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Ignat Korchagin <ignat@cloudflare.com> Signed-off-by:
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Russell King authored
Commit a3c0f847 upstream. Spectre variant 1 attacks are about this sequence of pseudo-code: index = load(user-manipulated pointer); access(base + index * stride); In order for the cache side-channel to work, the access() must me made to memory which userspace can detect whether cache lines have been loaded. On 32-bit ARM, this must be either user accessible memory, or a kernel mapping of that same user accessible memory. The problem occurs when the load() speculatively loads privileged data, and the subsequent access() is made to user accessible memory. Any load() which makes use of a user-maniplated pointer is a potential problem if the data it has loaded is used in a subsequent access. This also applies for the access() if the data loaded by that access is used by a subsequent access. Harden the get_user() accessors against Spectre attacks by forcing out of bounds addresses to a NULL pointer. This prevents get_user() being used as the load() step above. As a side effect, put_user() will also be affected even though it isn't implicated. Also harden copy_from_user() by redoing the bounds check within the arm_copy_from_user() code, and NULLing the pointer if out of bounds. Acked-by:
Mark Rutland <mark.rutland@arm.com> Signed-off-by:
Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by:
David A. Long <dave.long@linaro.org> Signed-off-by:
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Russell King authored
Commit b1cd0a14 upstream. Fixing __get_user() for spectre variant 1 is not sane: we would have to add address space bounds checking in order to validate that the location should be accessed, and then zero the address if found to be invalid. Since __get_user() is supposed to avoid the bounds check, and this is exactly what get_user() does, there's no point having two different implementations that are doing the same thing. So, when the Spectre workarounds are required, make __get_user() an alias of get_user(). Acked-by:
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Russell King authored
Commit d09fbb32 upstream. Borrow the x86 implementation of __inttype() to use in get_user() to select an integer type suitable to temporarily hold the result value. This is necessary to avoid propagating the volatile nature of the result argument, which can cause the following warning: lib/iov_iter.c:413:5: warning: optimization may eliminate reads and/or writes to register variables [-Wvolatile-register-var] Acked-by:
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Russell King authored
Commit 8c8484a1 upstream. __get_user_error() is used as a fast accessor to make copying structure members as efficient as possible. However, with software PAN and the recent Spectre variant 1, the efficiency is reduced as these are no longer fast accessors. In the case of software PAN, it has to switch the domain register around each access, and with Spectre variant 1, it would have to repeat the access_ok() check for each access. Rather than using __get_user_error() to copy each semops element member, copy each semops element in full using __copy_from_user(). Acked-by:
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Russell King authored
Commit 42019fc5 upstream. __get_user_error() is used as a fast accessor to make copying structure members in the signal handling path as efficient as possible. However, with software PAN and the recent Spectre variant 1, the efficiency is reduced as these are no longer fast accessors. In the case of software PAN, it has to switch the domain register around each access, and with Spectre variant 1, it would have to repeat the access_ok() check for each access. Use __copy_from_user() rather than __get_user_err() for individual members when restoring VFP state. Acked-by:
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Russell King authored
Commit c32cd419 upstream. __get_user_error() is used as a fast accessor to make copying structure members in the signal handling path as efficient as possible. However, with software PAN and the recent Spectre variant 1, the efficiency is reduced as these are no longer fast accessors. In the case of software PAN, it has to switch the domain register around each access, and with Spectre variant 1, it would have to repeat the access_ok() check for each access. It becomes much more efficient to use __copy_from_user() instead, so let's use this for the ARM integer registers. Acked-by:
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Russell King authored
Commit 10573ae5 upstream. Prevent speculation at the syscall table decoding by clamping the index used to zero on invalid system call numbers, and using the csdb speculative barrier. Signed-off-by:
Tony Lindgren <tony@atomide.com> Reviewed-by:
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Russell King authored
Commit 1d4238c5 upstream. Add an implementation of the array_index_mask_nospec() function for mitigating Spectre variant 1 throughout the kernel. Signed-off-by:
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Russell King authored
Commit a78d1565 upstream. Add assembly and C macros for the new CSDB instruction. Signed-off-by:
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Russell King authored
Commit add56098 upstream. Report support for SMCCC_ARCH_WORKAROUND_1 to KVM guests for affected CPUs. Signed-off-by:
Marc Zyngier <marc.zyngier@arm.com> Signed-off-by:
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Russell King authored
Commit b800acfc upstream. We want SMCCC_ARCH_WORKAROUND_1 to be fast. As fast as possible. So let's intercept it as early as we can by testing for the function call number as soon as we've identified a HVC call coming from the guest. Signed-off-by:
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Russell King authored
Commit 3c908e16 upstream. Include Brahma B15 in the Spectre v2 KVM workarounds. Signed-off-by:
Florian Fainelli <f.fainelli@gmail.com> Boot-tested-by:
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Marc Zyngier authored
Commit 0c47ac8c upstream. In order to avoid aliasing attacks against the branch predictor on Cortex-A15, let's invalidate the BTB on guest exit, which can only be done by invalidating the icache (with ACTLR[0] being set). We use the same hack as for A12/A17 to perform the vector decoding. Signed-off-by:
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Marc Zyngier authored
Commit 3f7e8e2e upstream. In order to avoid aliasing attacks against the branch predictor, let's invalidate the BTB on guest exit. This is made complicated by the fact that we cannot take a branch before invalidating the BTB. We only apply this to A12 and A17, which are the only two ARM cores on which this useful. Signed-off-by:
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Russell King authored
Commit c44f366e upstream. Warn at error level if the context switching function is not what we are expecting. This can happen with big.Little systems, which we currently do not support. Signed-off-by:
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Russell King authored
Commit 10115105 upstream. Add firmware based hardening for cores that require more complex handling in firmware. Signed-off-by:
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Russell King authored
Commit f5fe12b1 upstream. In order to prevent aliasing attacks on the branch predictor, invalidate the BTB or instruction cache on CPUs that are known to be affected when taking an abort on a address that is outside of a user task limit: Cortex A8, A9, A12, A17, A73, A75: flush BTB. Cortex A15, Brahma B15: invalidate icache. If the IBE bit is not set, then there is little point to enabling the workaround. Signed-off-by:
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Russell King authored
Commit e388b802 upstream. When the branch predictor hardening is enabled, firmware must have set the IBE bit in the auxiliary control register. If this bit has not been set, the Spectre workarounds will not be functional. Add validation that this bit is set, and print a warning at alert level if this is not the case. Signed-off-by:
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Russell King authored
Commit 06c23f5f upstream. Required manual merge of arch/arm/mm/proc-v7.S. Harden the branch predictor against Spectre v2 attacks on context switches for ARMv7 and later CPUs. We do this by: Cortex A9, A12, A17, A73, A75: invalidating the BTB. Cortex A15, Brahma B15: invalidating the instruction cache. Cortex A57 and Cortex A72 are not addressed in this patch. Cortex R7 and Cortex R8 are also not addressed as we do not enforce memory protection on these cores. Signed-off-by:
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Russell King authored
Commit c58d237d upstream. Add a Kconfig symbol for CPUs which are vulnerable to the Spectre attacks. Signed-off-by:
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Russell King authored
Commit 9d3a0492 upstream. Add support for per-processor bug checking - each processor function descriptor gains a function pointer for this check, which must not be an __init function. If non-NULL, this will be called whenever a CPU enters the kernel via which ever path (boot CPU, secondary CPU startup, CPU resuming, etc.) This allows processor specific bug checks to validate that workaround bits are properly enabled by firmware via all entry paths to the kernel. Signed-off-by:
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Russell King authored
Commit 26602161 upstream. Check for CPU bugs when secondary processors are being brought online, and also when CPUs are resuming from a low power mode. This gives an opportunity to check that processor specific bug workarounds are correctly enabled for all paths that a CPU re-enters the kernel. Signed-off-by:
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Russell King authored
Commit a5b9177f upstream. Prepare the processor bug infrastructure so that it can be expanded to check for per-processor bugs. Signed-off-by:
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Russell King authored
Commit f5683e76 upstream. Add CPU part numbers for Cortex A53, A57, A72, A73, A75 and the Broadcom Brahma B15 CPU. Signed-off-by:
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Roman Gushchin authored
commit 7aaf7727 upstream. Don't show nr_indirectly_reclaimable in /proc/vmstat, because there is no need to export this vm counter to userspace, and some changes are expected in reclaimable object accounting, which can alter this counter. Link: http://lkml.kernel.org/r/20180425191422.9159-1-guro@fb.comSigned-off-by:
Roman Gushchin <guro@fb.com> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Reviewed-by:
Andrew Morton <akpm@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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Roman Gushchin authored
commit d79f7aa4 upstream. Indirectly reclaimable memory can consume a significant part of total memory and it's actually reclaimable (it will be released under actual memory pressure). So, the overcommit logic should treat it as free. Otherwise, it's possible to cause random system-wide memory allocation failures by consuming a significant amount of memory by indirectly reclaimable memory, e.g. dentry external names. If overcommit policy GUESS is used, it might be used for denial of service attack under some conditions. The following program illustrates the approach. It causes the kernel to allocate an unreclaimable kmalloc-256 chunk for each stat() call, so that at some point the overcommit logic may start blocking large allocation system-wide. int main() { char buf[256]; unsigned long i; struct stat statbuf; buf[0] = '/'; for (i = 1; i < sizeof(buf); i++) buf[i] = '_'; for (i = 0; 1; i++) { sprintf(&buf[248], "%8lu", i); stat(buf, &statbuf); } return 0; } This patch in combination with related indirectly reclaimable memory patches closes this issue. Link: http://lkml.kernel.org/r/20180313130041.8078-1-guro@fb.comSigned-off-by:
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Roman Gushchin authored
commit f1782c9b upstream. I received a report about suspicious growth of unreclaimable slabs on some machines. I've found that it happens on machines with low memory pressure, and these unreclaimable slabs are external names attached to dentries. External names are allocated using generic kmalloc() function, so they are accounted as unreclaimable. But they are held by dentries, which are reclaimable, and they will be reclaimed under the memory pressure. In particular, this breaks MemAvailable calculation, as it doesn't take unreclaimable slabs into account. This leads to a silly situation, when a machine is almost idle, has no memory pressure and therefore has a big dentry cache. And the resulting MemAvailable is too low to start a new workload. To address the issue, the NR_INDIRECTLY_RECLAIMABLE_BYTES counter is used to track the amount of memory, consumed by external names. The counter is increased in the dentry allocation path, if an external name structure is allocated; and it's decreased in the dentry freeing path. To reproduce the problem I've used the following Python script: import os for iter in range (0, 10000000): try: name = ("/some_long_name_%d" % iter) + "_" * 220 os.stat(name) except Exception: pass Without this patch: $ cat /proc/meminfo | grep MemAvailable MemAvailable: 7811688 kB $ python indirect.py $ cat /proc/meminfo | grep MemAvailable MemAvailable: 2753052 kB With the patch: $ cat /proc/meminfo | grep MemAvailable MemAvailable: 7809516 kB $ python indirect.py $ cat /proc/meminfo | grep MemAvailable MemAvailable: 7749144 kB [guro@fb.com: fix indirectly reclaimable memory accounting for CONFIG_SLOB] Link: http://lkml.kernel.org/r/20180312194140.19517-1-guro@fb.com [guro@fb.com: fix indirectly reclaimable memory accounting] Link: http://lkml.kernel.org/r/20180313125701.7955-1-guro@fb.com Link: http://lkml.kernel.org/r/20180305133743.12746-5-guro@fb.comSigned-off-by:
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Roman Gushchin authored
commit 034ebf65 upstream. Adjust /proc/meminfo MemAvailable calculation by adding the amount of indirectly reclaimable memory (rounded to the PAGE_SIZE). Link: http://lkml.kernel.org/r/20180305133743.12746-4-guro@fb.comSigned-off-by:
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Roman Gushchin authored
commit eb592546 upstream. Patch series "indirectly reclaimable memory", v2. This patchset introduces the concept of indirectly reclaimable memory and applies it to fix the issue of when a big number of dentries with external names can significantly affect the MemAvailable value. This patch (of 3): Introduce a concept of indirectly reclaimable memory and adds the corresponding memory counter and /proc/vmstat item. Indirectly reclaimable memory is any sort of memory, used by the kernel (except of reclaimable slabs), which is actually reclaimable, i.e. will be released under memory pressure. The counter is in bytes, as it's not always possible to count such objects in pages. The name contains BYTES by analogy to NR_KERNEL_STACK_KB. Link: http://lkml.kernel.org/r/20180305133743.12746-2-guro@fb.comSigned-off-by:
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