#2 Remove LibreSSL in Base

opened 7 months ago by shawn.webb · 1 comments

The version of LibreSSL in HardenedBSD is horribly out-of-date. As there is no real maintainer of LibreSSL in HardenedBSD, remove it from HardenedBSD base. This will help with diff reduction as well.

The version of LibreSSL in HardenedBSD is horribly out-of-date. As there is no real maintainer of LibreSSL in HardenedBSD, remove it from HardenedBSD base. This will help with diff reduction as well.
shawn.webb self-assigned this 7 months ago
shawn.webb added the
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label 7 months ago
shawn.webb commented 7 months ago

LibreSSL and OpenNTPD have now been removed from HardenedBSD’s hardened/current/master branch.

LibreSSL and OpenNTPD have now been removed from HardenedBSD's `hardened/current/master` branch.
shawn.webb closed this issue 7 months ago
shawn.webb referenced this issue from a commit 2 months ago
Reset the DAC to 6-bit mode before calling the BIOS to set the screen mode. This works around bugs in at least 2 Intel BIOSes for our subsequent setting of the DAC back to 8-bit mode. The bug caused dark (mostly 1/4-intensity) colors for all except the first setting to a VESA graphics mode (including for settings to the current mode). Remove restoration (with less bits) of the palette in vesa_unload() after resetting the DAC to 6-bit mode. Depend on the BIOS to keep the palette consistent with the DAC for the simpler reset case like we do everywhere else in places that are actually important. Setting the video mode should reset everything to defaults, although we usually don't want that. Even the buggy BIOSes set the DAC to the default 6-bit mode, and set the palette to a default that matches the DAC. We don't undo the reset for most things, but we do undo it for the DAC (more precisely, we change to an 8-bit DAC if possible, and this is the only way that we set to an 8-bit DAC; it is accidental that if the DAC was in 8-bit mode from a previous mode switch then setting it to 8-bit mode is an undo). The buggy BIOSes are confused by our setting of the DAC to 8-bit mode in the "undo" case. They should multiply palette entries by 4 to match, but they actually leave all palette entries except #2 (green) and #248-255 (unused) untouched. Green is mysteriously scaled from 0x2a to 0x6a, and #248-255 are scaled correctly. Our support for the 8-bit DAC had almost no effect except to enable bugs. Syscons barely supports 16 colors, so it doesn't benefit much from having a palette with 16 million colors instead of only 256K. Applications can manage the palette using FBIO_{GET,SET}PALETTE, but the palette managed by this is only used in the less interesting modes (text and non-truecolor graphics modes up to 8 bits wide), and the kernel loses the changes on any mode switch (including to another vt in a different mode).
shawn.webb referenced this issue from a commit 2 months ago
shawn.webb referenced this issue from a commit 2 months ago
Introduce aw_syscon(4) for earlier attachment Attaching syscon_generic earlier than BUS_PASS_DEFAULT makes it more difficult for specific syscon drivers to attach to the syscon node and to get ordering right. Further discussion yielded the following set of decisions: - Move syscon_generic to BUS_PASS_DEFAULT - If a platform needs a syscon with different attach order or probe behavior, it should subclass syscon_generic and match on the SoC specific compat string - When we come across a need for a syscon that attaches earlier but only specifies compatible = "syscon", we should create a syscon_exclusive driver that provides generic access but probes earlier and only matches if "syscon" is the only compatible. Such fdt nodes do exist in the wild right now, but we don't really use them at the moment. Additionally: - Any syscon provider that has needs any more complex than a spinlock solely for syscon access and a single memory resource should subclass syscon directly rather than attempting to subclass syscon_generic or add complexity to it. syscon_generic's attach/detach methods may be made public should the need arise to subclass it with additional attach/detach behavior. We introduce aw_syscon(4) that just subclasses syscon_generic but probes earlier to meet our requirements for if_awg and implements #2 above for this specific situation. It currently only matches a64/a83t/h3 since these are the only platforms that really need it at the time being. Discussed with: ian Reviewed by: manu, andrew, bcr (manpages, content unchanged since review) Differential Revision: https://reviews.freebsd.org/D13793
shawn.webb referenced this issue from a commit 2 months ago
Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to 6.0.0 (branches/release_60 r324090). This introduces retpoline support, with the -mretpoline flag. The upstream initial commit message (r323155 by Chandler Carruth) contains quite a bit of explanation. Quoting: Introduce the "retpoline" x86 mitigation technique for variant #2 of the speculative execution vulnerabilities disclosed today, specifically identified by CVE-2017-5715, "Branch Target Injection", and is one of the two halves to Spectre. Summary: First, we need to explain the core of the vulnerability. Note that this is a very incomplete description, please see the Project Zero blog post for details: https://googleprojectzero.blogspot.com/2018/01/reading-privileged-memory-with-side.html The basis for branch target injection is to direct speculative execution of the processor to some "gadget" of executable code by poisoning the prediction of indirect branches with the address of that gadget. The gadget in turn contains an operation that provides a side channel for reading data. Most commonly, this will look like a load of secret data followed by a branch on the loaded value and then a load of some predictable cache line. The attacker then uses timing of the processors cache to determine which direction the branch took *in the speculative execution*, and in turn what one bit of the loaded value was. Due to the nature of these timing side channels and the branch predictor on Intel processors, this allows an attacker to leak data only accessible to a privileged domain (like the kernel) back into an unprivileged domain. The goal is simple: avoid generating code which contains an indirect branch that could have its prediction poisoned by an attacker. In many cases, the compiler can simply use directed conditional branches and a small search tree. LLVM already has support for lowering switches in this way and the first step of this patch is to disable jump-table lowering of switches and introduce a pass to rewrite explicit indirectbr sequences into a switch over integers. However, there is no fully general alternative to indirect calls. We introduce a new construct we call a "retpoline" to implement indirect calls in a non-speculatable way. It can be thought of loosely as a trampoline for indirect calls which uses the RET instruction on x86. Further, we arrange for a specific call->ret sequence which ensures the processor predicts the return to go to a controlled, known location. The retpoline then "smashes" the return address pushed onto the stack by the call with the desired target of the original indirect call. The result is a predicted return to the next instruction after a call (which can be used to trap speculative execution within an infinite loop) and an actual indirect branch to an arbitrary address. On 64-bit x86 ABIs, this is especially easily done in the compiler by using a guaranteed scratch register to pass the target into this device. For 32-bit ABIs there isn't a guaranteed scratch register and so several different retpoline variants are introduced to use a scratch register if one is available in the calling convention and to otherwise use direct stack push/pop sequences to pass the target address. This "retpoline" mitigation is fully described in the following blog post: https://support.google.com/faqs/answer/7625886 We also support a target feature that disables emission of the retpoline thunk by the compiler to allow for custom thunks if users want them. These are particularly useful in environments like kernels that routinely do hot-patching on boot and want to hot-patch their thunk to different code sequences. They can write this custom thunk and use `-mretpoline-external-thunk` *in addition* to `-mretpoline`. In this case, on x86-64 thu thunk names must be: ``` __llvm_external_retpoline_r11 ``` or on 32-bit: ``` __llvm_external_retpoline_eax __llvm_external_retpoline_ecx __llvm_external_retpoline_edx __llvm_external_retpoline_push ``` And the target of the retpoline is passed in the named register, or in the case of the `push` suffix on the top of the stack via a `pushl` instruction. There is one other important source of indirect branches in x86 ELF binaries: the PLT. These patches also include support for LLD to generate PLT entries that perform a retpoline-style indirection. The only other indirect branches remaining that we are aware of are from precompiled runtimes (such as crt0.o and similar). The ones we have found are not really attackable, and so we have not focused on them here, but eventually these runtimes should also be replicated for retpoline-ed configurations for completeness. For kernels or other freestanding or fully static executables, the compiler switch `-mretpoline` is sufficient to fully mitigate this particular attack. For dynamic executables, you must compile *all* libraries with `-mretpoline` and additionally link the dynamic executable and all shared libraries with LLD and pass `-z retpolineplt` (or use similar functionality from some other linker). We strongly recommend also using `-z now` as non-lazy binding allows the retpoline-mitigated PLT to be substantially smaller. When manually apply similar transformations to `-mretpoline` to the Linux kernel we observed very small performance hits to applications running typic al workloads, and relatively minor hits (approximately 2%) even for extremely syscall-heavy applications. This is largely due to the small number of indirect branches that occur in performance sensitive paths of the kernel. When using these patches on statically linked applications, especially C++ applications, you should expect to see a much more dramatic performance hit. For microbenchmarks that are switch, indirect-, or virtual-call heavy we have seen overheads ranging from 10% to 50%. However, real-world workloads exhibit substantially lower performance impact. Notably, techniques such as PGO and ThinLTO dramatically reduce the impact of hot indirect calls (by speculatively promoting them to direct calls) and allow optimized search trees to be used to lower switches. If you need to deploy these techniques in C++ applications, we *strongly* recommend that you ensure all hot call targets are statically linked (avoiding PLT indirection) and use both PGO and ThinLTO. Well tuned servers using all of these techniques saw 5% - 10% overhead from the use of retpoline. We will add detailed documentation covering these components in subsequent patches, but wanted to make the core functionality available as soon as possible. Happy for more code review, but we'd really like to get these patches landed and backported ASAP for obvious reasons. We're planning to backport this to both 6.0 and 5.0 release streams and get a 5.0 release with just this cherry picked ASAP for distros and vendors. This patch is the work of a number of people over the past month: Eric, Reid, Rui, and myself. I'm mailing it out as a single commit due to the time sensitive nature of landing this and the need to backport it. Huge thanks to everyone who helped out here, and everyone at Intel who helped out in discussions about how to craft this. Also, credit goes to Paul Turner (at Google, but not an LLVM contributor) for much of the underlying retpoline design. Reviewers: echristo, rnk, ruiu, craig.topper, DavidKreitzer Subscribers: sanjoy, emaste, mcrosier, mgorny, mehdi_amini, hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D41723 MFC after: 3 months X-MFC-With: r327952 PR: 224669
shawn.webb referenced this issue from a commit 2 months ago
HBSD: Pull in libarchive/libarchive@65a23f5dbee4497064e9bb467f81138a62b0dae1 From the commit in libarchive: ``` Fuzzing with CRCs disabled revealed that a call to get_uncompressed_data() would sometimes fail to return at least 'minimum' bytes. This can cause the crc32() invocation in header_bytes to read off into invalid memory. A specially crafted archive can use this to cause a crash. An ASAN trace is below, but ASAN is not required - an uninstrumented binary will also crash. ==7719==ERROR: AddressSanitizer: SEGV on unknown address 0x631000040000 (pc 0x7fbdb3b3ec1d bp 0x7ffe77a51310 sp 0x7ffe77a51150 T0) ==7719==The signal is caused by a READ memory access. #0 0x7fbdb3b3ec1c in crc32_z (/lib/x86_64-linux-gnu/libz.so.1+0x2c1c) #1 0x84f5eb in header_bytes (/tmp/libarchive/bsdtar+0x84f5eb) #2 0x856156 in read_Header (/tmp/libarchive/bsdtar+0x856156) #3 0x84e134 in slurp_central_directory (/tmp/libarchive/bsdtar+0x84e134) #4 0x849690 in archive_read_format_7zip_read_header (/tmp/libarchive/bsdtar+0x849690) #5 0x5713b7 in _archive_read_next_header2 (/tmp/libarchive/bsdtar+0x5713b7) #6 0x570e63 in _archive_read_next_header (/tmp/libarchive/bsdtar+0x570e63) #7 0x6f08bd in archive_read_next_header (/tmp/libarchive/bsdtar+0x6f08bd) #8 0x52373f in read_archive (/tmp/libarchive/bsdtar+0x52373f) #9 0x5257be in tar_mode_x (/tmp/libarchive/bsdtar+0x5257be) #10 0x51daeb in main (/tmp/libarchive/bsdtar+0x51daeb) #11 0x7fbdb27cab96 in __libc_start_main /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:310 #12 0x41dd09 in _start (/tmp/libarchive/bsdtar+0x41dd09) This was primarly done with afl and FairFuzz. Some early corpus entries may have been generated by qsym. ``` Signed-off-by: Shawn Webb <shawn.webb@hardenedbsd.org> Sponsored-by: SoldierX
shawn.webb referenced this issue from a commit 1 month ago
Merge commit 1ce07cd614be from llvm git (by me): Instantiate Error in Target::GetEntryPointAddress() only when necessary When Target::GetEntryPointAddress() calls exe_module->GetObjectFile()->GetEntryPointAddress(), and the returned entry_addr is valid, it can immediately be returned. However, just before that, an llvm::Error value has been setup, but in this case it is not consumed before returning, like is done further below in the function. In https://bugs.freebsd.org/248745 we got a bug report for this, where a very simple test case aborts and dumps core: * thread #1, name = 'testcase', stop reason = breakpoint 1.1 frame #0: 0x00000000002018d4 testcase`main(argc=1, argv=0x00007fffffffea18) at testcase.c:3:5 1 int main(int argc, char *argv[]) 2 { -> 3 return 0; 4 } (lldb) p argc Program aborted due to an unhandled Error: Error value was Success. (Note: Success values must still be checked prior to being destroyed). Thread 1 received signal SIGABRT, Aborted. thr_kill () at thr_kill.S:3 3 thr_kill.S: No such file or directory. (gdb) bt #0 thr_kill () at thr_kill.S:3 #1 0x00000008049a0004 in __raise (s=6) at /usr/src/lib/libc/gen/raise.c:52 #2 0x0000000804916229 in abort () at /usr/src/lib/libc/stdlib/abort.c:67 #3 0x000000000451b5f5 in fatalUncheckedError () at /usr/src/contrib/llvm-project/llvm/lib/Support/Error.cpp:112 #4 0x00000000019cf008 in GetEntryPointAddress () at /usr/src/contrib/llvm-project/llvm/include/llvm/Support/Error.h:267 #5 0x0000000001bccbd8 in ConstructorSetup () at /usr/src/contrib/llvm-project/lldb/source/Target/ThreadPlanCallFunction.cpp:67 #6 0x0000000001bcd2c0 in ThreadPlanCallFunction () at /usr/src/contrib/llvm-project/lldb/source/Target/ThreadPlanCallFunction.cpp:114 #7 0x00000000020076d4 in InferiorCallMmap () at /usr/src/contrib/llvm-project/lldb/source/Plugins/Process/Utility/InferiorCallPOSIX.cpp:97 #8 0x0000000001f4be33 in DoAllocateMemory () at /usr/src/contrib/llvm-project/lldb/source/Plugins/Process/FreeBSD/ProcessFreeBSD.cpp:604 #9 0x0000000001fe51b9 in AllocatePage () at /usr/src/contrib/llvm-project/lldb/source/Target/Memory.cpp:347 #10 0x0000000001fe5385 in AllocateMemory () at /usr/src/contrib/llvm-project/lldb/source/Target/Memory.cpp:383 #11 0x0000000001974da2 in AllocateMemory () at /usr/src/contrib/llvm-project/lldb/source/Target/Process.cpp:2301 #12 CanJIT () at /usr/src/contrib/llvm-project/lldb/source/Target/Process.cpp:2331 #13 0x0000000001a1bf3d in Evaluate () at /usr/src/contrib/llvm-project/lldb/source/Expression/UserExpression.cpp:190 #14 0x00000000019ce7a2 in EvaluateExpression () at /usr/src/contrib/llvm-project/lldb/source/Target/Target.cpp:2372 #15 0x0000000001ad784c in EvaluateExpression () at /usr/src/contrib/llvm-project/lldb/source/Commands/CommandObjectExpression.cpp:414 #16 0x0000000001ad86ae in DoExecute () at /usr/src/contrib/llvm-project/lldb/source/Commands/CommandObjectExpression.cpp:646 #17 0x0000000001a5e3ed in Execute () at /usr/src/contrib/llvm-project/lldb/source/Interpreter/CommandObject.cpp:1003 #18 0x0000000001a6c4a3 in HandleCommand () at /usr/src/contrib/llvm-project/lldb/source/Interpreter/CommandInterpreter.cpp:1762 #19 0x0000000001a6f98c in IOHandlerInputComplete () at /usr/src/contrib/llvm-project/lldb/source/Interpreter/CommandInterpreter.cpp:2760 #20 0x0000000001a90b08 in Run () at /usr/src/contrib/llvm-project/lldb/source/Core/IOHandler.cpp:548 #21 0x00000000019a6c6a in ExecuteIOHandlers () at /usr/src/contrib/llvm-project/lldb/source/Core/Debugger.cpp:903 #22 0x0000000001a70337 in RunCommandInterpreter () at /usr/src/contrib/llvm-project/lldb/source/Interpreter/CommandInterpreter.cpp:2946 #23 0x0000000001d9d812 in RunCommandInterpreter () at /usr/src/contrib/llvm-project/lldb/source/API/SBDebugger.cpp:1169 #24 0x0000000001918be8 in MainLoop () at /usr/src/contrib/llvm-project/lldb/tools/driver/Driver.cpp:675 #25 0x000000000191a114 in main () at /usr/src/contrib/llvm-project/lldb/tools/driver/Driver.cpp:890 Fix the incorrect error catch by only instantiating an Error object if it is necessary. Reviewed By: JDevlieghere Differential Revision: https://reviews.llvm.org/D86355 This should fix lldb aborting as described in the scenario above. Reported by: dmgk PR: 248745
hardenedbsd-services referenced this issue from a commit 1 month ago
Fix hangs with processes stuck sleeping on btalloc on i386. r358097 introduced a problem for i386, where kernel builds will intermittently get hung, typically with many processes sleeping on "btalloc". I know nothing about VM, but received assistance from rlibby@ and markj@. rlibby@ stated the following: It looks like the problem is that for systems that do not have UMA_MD_SMALL_ALLOC, we do uma_zone_set_allocf(vmem_bt_zone, vmem_bt_alloc); but we haven't set an appropriate free function. This is probably why UMA_ZONE_NOFREE was originally there. When NOFREE was removed, it was appropriate for systems with uma_small_alloc. So by default we get page_free as our free function. That calls kmem_free, which calls vmem_free ... but we do our allocs with vmem_xalloc. I'm not positive, but I think the problem is that in effect we vmem_xalloc -> vmem_free, not vmem_xfree. Three possible fixes: 1: The one you tested, but this is not best for systems with uma_small_alloc. 2: Pass UMA_ZONE_NOFREE conditional on UMA_MD_SMALL_ALLOC. 3: Actually provide an appropriate vmem_bt_free function. I think we should just do option 2 with a comment, it's simple and it's what we used to do. I'm not sure how much benefit we would see from option 3, but it's more work. This patch implements #2. I haven't done a comment, since I don't know what the problem is. markj@ noted the following: I think the suggested patch is ok, but not for the reason stated. On platforms without a direct map the problem is: to allocate btags we need a slab, and to allocate a slab we need to map a page, and to map a page we need to allocate btags. We handle this recursion using a custom slab allocator which specifies M_USE_RESERVE, allowing it to dip into a reserve of free btags. Because the returned slab can be used to keep the reserve populated, this ensures that there are always enough free btags available to handle the recursion. UMA_ZONE_NOFREE ensures that we never reclaim free slabs from the zone. However, when it was removed, an apparent bug in UMA was exposed: keg_drain() ignores the reservation set by uma_zone_reserve() in vmem_startup(). So under memory pressure we reclaim the free btags that are needed to break the recursion. That's why adding _NOFREE back fixes the problem: it disables the reclamation. We could perhaps fix it more cleverly, by modifying keg_drain() to always leave uk_reserve slabs available. markj@'s initial patch failed testing, so committing this patch was agreed upon as the interim solution. Either rlibby@ or markj@ might choose to add a comment to it. PR: 248008 Reviewed by: rlibby, markj
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