kernel/linux.git/lib, branch v3.16.76

lib/scatterlist: Fix mapping iterator when sg->offset is greater than PAGE_SIZE

2019-10-31T22:15:01+00:00

commit aeb87246537a83c2aff482f3f34a2e0991e02cbc upstream. All mapping iterator logic is based on the assumption that sg->offset is always lower than PAGE_SIZE. But there are situations where sg->offset is such that the SG item is on the second page. In that case sg_copy_to_buffer() fails properly copying the data into the buffer. One of the reason is that the data will be outside the kmapped area used to access that data. This patch fixes the issue by adjusting the mapping iterator offset and pgoffset fields such that offset is always lower than PAGE_SIZE. Signed-off-by: Christophe Leroy Fixes: 4225fc8555a9 ("lib/scatterlist: use page iterator in the mapping iterator") Signed-off-by: Herbert Xu Signed-off-by: Ben Hutchings

lib/mpi: Fix karactx leak in mpi_powm

2019-10-05T15:20:08+00:00

commit c8ea9fce2baf7b643384f36f29e4194fa40d33a6 upstream. Sometimes mpi_powm will leak karactx because a memory allocation failure causes a bail-out that skips the freeing of karactx. This patch moves the freeing of karactx to the end of the function like everything else so that it can't be skipped. Reported-by: syzbot+f7baccc38dcc1e094e77@syzkaller.appspotmail.com Fixes: cdec9cb5167a ("crypto: GnuPG based MPI lib - source files...") Signed-off-by: Herbert Xu Reviewed-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Ben Hutchings

kobject: Don't trigger kobject_uevent(KOBJ_REMOVE) twice.

2019-09-23T20:11:36+00:00

commit c03a0fd0b609e2f5c669c2b7f27c8e1928e9196e upstream. syzbot is hitting use-after-free bug in uinput module [1]. This is because kobject_uevent(KOBJ_REMOVE) is called again due to commit 0f4dafc0563c6c49 ("Kobject: auto-cleanup on final unref") after memory allocation fault injection made kobject_uevent(KOBJ_REMOVE) from device_del() from input_unregister_device() fail, while uinput_destroy_device() is expecting that kobject_uevent(KOBJ_REMOVE) is not called after device_del() from input_unregister_device() completed. That commit intended to catch cases where nobody even attempted to send "remove" uevents. But there is no guarantee that an event will ultimately be sent. We are at the point of no return as far as the rest of the kernel is concerned; there are no repeats or do-overs. Also, it is not clear whether some subsystem depends on that commit. If no subsystem depends on that commit, it will be better to remove the state_{add,remove}_uevent_sent logic. But we don't want to risk a regression (in a patch which will be backported) by trying to remove that logic. Therefore, as a first step, let's avoid the use-after-free bug by making sure that kobject_uevent(KOBJ_REMOVE) won't be triggered twice. [1] https://syzkaller.appspot.com/bug?id=8b17c134fe938bbddd75a45afaa9e68af43a362d Reported-by: syzbot Analyzed-by: Dmitry Torokhov Fixes: 0f4dafc0563c6c49 ("Kobject: auto-cleanup on final unref") Cc: Kay Sievers Signed-off-by: Tetsuo Handa Signed-off-by: Greg Kroah-Hartman [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings

siphash: implement HalfSipHash1-3 for hash tables

2019-08-20T18:01:56+00:00

commit 1ae2324f732c9c4e2fa4ebd885fa1001b70d52e1 upstream. HalfSipHash, or hsiphash, is a shortened version of SipHash, which generates 32-bit outputs using a weaker 64-bit key. It has *much* lower security margins, and shouldn't be used for anything too sensitive, but it could be used as a hashtable key function replacement, if the output is never exposed, and if the security requirement is not too high. The goal is to make this something that performance-critical jhash users would be willing to use. On 64-bit machines, HalfSipHash1-3 is slower than SipHash1-3, so we alias SipHash1-3 to HalfSipHash1-3 on those systems. 64-bit x86_64: [ 0.509409] test_siphash: SipHash2-4 cycles: 4049181 [ 0.510650] test_siphash: SipHash1-3 cycles: 2512884 [ 0.512205] test_siphash: HalfSipHash1-3 cycles: 3429920 [ 0.512904] test_siphash: JenkinsHash cycles: 978267 So, we map hsiphash() -> SipHash1-3 32-bit x86: [ 0.509868] test_siphash: SipHash2-4 cycles: 14812892 [ 0.513601] test_siphash: SipHash1-3 cycles: 9510710 [ 0.515263] test_siphash: HalfSipHash1-3 cycles: 3856157 [ 0.515952] test_siphash: JenkinsHash cycles: 1148567 So, we map hsiphash() -> HalfSipHash1-3 hsiphash() is roughly 3 times slower than jhash(), but comes with a considerable security improvement. Signed-off-by: Jason A. Donenfeld Reviewed-by: Jean-Philippe Aumasson Signed-off-by: David S. Miller [bwh: Backported to 3.16 to avoid a build regression for WireGuard with only part of the siphash API available] Signed-off-by: Ben Hutchings

siphash: add cryptographically secure PRF

2019-08-13T11:39:32+00:00

commit 2c956a60778cbb6a27e0c7a8a52a91378c90e1d1 upstream. SipHash is a 64-bit keyed hash function that is actually a cryptographically secure PRF, like HMAC. Except SipHash is super fast, and is meant to be used as a hashtable keyed lookup function, or as a general PRF for short input use cases, such as sequence numbers or RNG chaining. For the first usage: There are a variety of attacks known as "hashtable poisoning" in which an attacker forms some data such that the hash of that data will be the same, and then preceeds to fill up all entries of a hashbucket. This is a realistic and well-known denial-of-service vector. Currently hashtables use jhash, which is fast but not secure, and some kind of rotating key scheme (or none at all, which isn't good). SipHash is meant as a replacement for jhash in these cases. There are a modicum of places in the kernel that are vulnerable to hashtable poisoning attacks, either via userspace vectors or network vectors, and there's not a reliable mechanism inside the kernel at the moment to fix it. The first step toward fixing these issues is actually getting a secure primitive into the kernel for developers to use. Then we can, bit by bit, port things over to it as deemed appropriate. While SipHash is extremely fast for a cryptographically secure function, it is likely a bit slower than the insecure jhash, and so replacements will be evaluated on a case-by-case basis based on whether or not the difference in speed is negligible and whether or not the current jhash usage poses a real security risk. For the second usage: A few places in the kernel are using MD5 or SHA1 for creating secure sequence numbers, syn cookies, port numbers, or fast random numbers. SipHash is a faster and more fitting, and more secure replacement for MD5 in those situations. Replacing MD5 and SHA1 with SipHash for these uses is obvious and straight-forward, and so is submitted along with this patch series. There shouldn't be much of a debate over its efficacy. Dozens of languages are already using this internally for their hash tables and PRFs. Some of the BSDs already use this in their kernels. SipHash is a widely known high-speed solution to a widely known set of problems, and it's time we catch-up. Signed-off-by: Jason A. Donenfeld Reviewed-by: Jean-Philippe Aumasson Cc: Linus Torvalds Cc: Eric Biggers Cc: David Laight Cc: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings

lib/string.c: implement a basic bcmp

2019-08-13T11:39:03+00:00

commit 5f074f3e192f10c9fade898b9b3b8812e3d83342 upstream. A recent optimization in Clang (r355672) lowers comparisons of the return value of memcmp against zero to comparisons of the return value of bcmp against zero. This helps some platforms that implement bcmp more efficiently than memcmp. glibc simply aliases bcmp to memcmp, but an optimized implementation is in the works. This results in linkage failures for all targets with Clang due to the undefined symbol. For now, just implement bcmp as a tailcail to memcmp to unbreak the build. This routine can be further optimized in the future. Other ideas discussed: * A weak alias was discussed, but breaks for architectures that define their own implementations of memcmp since aliases to declarations are not permitted (only definitions). Arch-specific memcmp implementations typically declare memcmp in C headers, but implement them in assembly. * -ffreestanding also is used sporadically throughout the kernel. * -fno-builtin-bcmp doesn't work when doing LTO. Link: https://bugs.llvm.org/show_bug.cgi?id=41035 Link: https://code.woboq.org/userspace/glibc/string/memcmp.c.html#bcmp Link: https://github.com/llvm/llvm-project/commit/8e16d73346f8091461319a7dfc4ddd18eedcff13 Link: https://github.com/ClangBuiltLinux/linux/issues/416 Link: http://lkml.kernel.org/r/20190313211335.165605-1-ndesaulniers@google.com Signed-off-by: Nick Desaulniers Reported-by: Nathan Chancellor Reported-by: Adhemerval Zanella Suggested-by: Arnd Bergmann Suggested-by: James Y Knight Suggested-by: Masahiro Yamada Suggested-by: Nathan Chancellor Suggested-by: Rasmus Villemoes Acked-by: Steven Rostedt (VMware) Reviewed-by: Nathan Chancellor Tested-by: Nathan Chancellor Reviewed-by: Masahiro Yamada Reviewed-by: Andy Shevchenko Cc: David Laight Cc: Rasmus Villemoes Cc: Namhyung Kim Cc: Greg Kroah-Hartman Cc: Alexander Shishkin Cc: Dan Williams Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

lib/div64.c: off by one in shift

2019-07-09T21:04:14+00:00

commit cdc94a37493135e355dfc0b0e086d84e3eadb50d upstream. fls counts bits starting from 1 to 32 (returns 0 for zero argument). If we add 1 we shift right one bit more and loose precision from divisor, what cause function incorect results with some numbers. Corrected code was tested in user-space, see bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202391 Link: http://lkml.kernel.org/r/1548686944-11891-1-git-send-email-sgruszka@redhat.com Fixes: 658716d19f8f ("div64_u64(): improve precision on 32bit platforms") Signed-off-by: Stanislaw Gruszka Reported-by: Siarhei Volkau Tested-by: Siarhei Volkau Acked-by: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings

devres: always use dev_name() in devm_ioremap_resource()

2019-07-09T21:03:52+00:00

commit 8d84b18f5678d3adfdb9375dfb0d968da2dc753d upstream. devm_ioremap_resource() prefers calling devm_request_mem_region() with a resource name instead of a device name -- this looks pretty iff a resource name isn't specified via a device tree with a "reg-names" property (in this case, a resource name is set to a device node's full name), but if it is, it doesn't really scale since these names are only unique to a given device node, not globally; so, looking at the output of 'cat /proc/iomem', you do not have an idea which memory region belongs to which device (see "dirmap", "regs", and "wbuf" lines below): 08000000-0bffffff : dirmap 48000000-bfffffff : System RAM 48000000-48007fff : reserved 48080000-48b0ffff : Kernel code 48b10000-48b8ffff : reserved 48b90000-48c7afff : Kernel data bc6a4000-bcbfffff : reserved bcc0f000-bebfffff : reserved bec0e000-bec0efff : reserved bec11000-bec11fff : reserved bec12000-bec14fff : reserved bec15000-bfffffff : reserved e6050000-e605004f : gpio@e6050000 e6051000-e605104f : gpio@e6051000 e6052000-e605204f : gpio@e6052000 e6053000-e605304f : gpio@e6053000 e6054000-e605404f : gpio@e6054000 e6055000-e605504f : gpio@e6055000 e6060000-e606050b : pin-controller@e6060000 e6e60000-e6e6003f : e6e60000.serial e7400000-e7400fff : ethernet@e7400000 ee200000-ee2001ff : regs ee208000-ee2080ff : wbuf I think that devm_request_mem_region() should be called with dev_name() despite the region names won't look as pretty as before (however, we gain more consistency with e.g. the serial driver: 08000000-0bffffff : ee200000.rpc 48000000-bfffffff : System RAM 48000000-48007fff : reserved 48080000-48b0ffff : Kernel code 48b10000-48b8ffff : reserved 48b90000-48c7afff : Kernel data bc6a4000-bcbfffff : reserved bcc0f000-bebfffff : reserved bec0e000-bec0efff : reserved bec11000-bec11fff : reserved bec12000-bec14fff : reserved bec15000-bfffffff : reserved e6050000-e605004f : e6050000.gpio e6051000-e605104f : e6051000.gpio e6052000-e605204f : e6052000.gpio e6053000-e605304f : e6053000.gpio e6054000-e605404f : e6054000.gpio e6055000-e605504f : e6055000.gpio e6060000-e606050b : e6060000.pin-controller e6e60000-e6e6003f : e6e60000.serial e7400000-e7400fff : e7400000.ethernet ee200000-ee2001ff : ee200000.rpc ee208000-ee2080ff : ee200000.rpc Fixes: 72f8c0bfa0de ("lib: devres: add convenience function to remap a resource") Signed-off-by: Sergei Shtylyov Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings

x86/cpufeature: Carve out X86_FEATURE_*

2019-05-22T22:15:08+00:00

commit cd4d09ec6f6c12a2cc3db5b7d8876a325a53545b upstream. Move them to a separate header and have the following dependency: x86/cpufeatures.h <- x86/processor.h <- x86/cpufeature.h This makes it easier to use the header in asm code and not include the whole cpufeature.h and add guards for asm. Suggested-by: H. Peter Anvin Signed-off-by: Borislav Petkov Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1453842730-28463-5-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar [bwh: Backported to 3.16 to avoid a dependency loop: - Drop some inapplicable changes - Move all the previously backported feature and bug flags across - Also change and lib/retpoline.S to use - Also include in , as the vdso fails to build without that - Adjust context] Signed-off-by: Ben Hutchings

x86/headers: Don't include asm/processor.h in asm/atomic.h

2019-05-22T22:15:07+00:00

commit 153a4334c439cfb62e1d31cee0c790ba4157813d upstream. asm/atomic.h doesn't really need asm/processor.h anymore. Everything it uses has moved to other header files. So remove that include. processor.h is a nasty header that includes lots of other headers and makes it prone to include loops. Removing the include here makes asm/atomic.h a "leaf" header that can be safely included in most other headers. The only fallout is in the lib/atomic tester which relied on this implicit include. Give it an explicit include. (the include is in ifdef because the user is also in ifdef) Signed-off-by: Andi Kleen Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/1449018060-1742-1-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar [bwh: Backported to 3.16 to avoid a dependency loop; adjusted context] Signed-off-by: Ben Hutchings