kernel/linux.git/lib, branch v5.9.16

zlib: export S390 symbols for zlib modules

2020-12-16T09:58:29+00:00

[ Upstream commit 11fb479ff5d9872ddff02dd533c16d60372c86b2 ] Fix build errors when ZLIB_INFLATE=m and ZLIB_DEFLATE=m and ZLIB_DFLTCC=y by exporting the 2 needed symbols in dfltcc_inflate.c. Fixes these build errors: ERROR: modpost: "dfltcc_inflate" [lib/zlib_inflate/zlib_inflate.ko] undefined! ERROR: modpost: "dfltcc_can_inflate" [lib/zlib_inflate/zlib_inflate.ko] undefined! Fixes: 126196100063 ("lib/zlib: add s390 hardware support for kernel zlib_inflate") Reported-by: kernel test robot Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Acked-by: Ilya Leoshkevich Cc: Mikhail Zaslonko Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Link: https://lkml.kernel.org/r/20201123191712.4882-1-rdunlap@infradead.org Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

lib/syscall: fix syscall registers retrieval on 32-bit platforms

2020-12-11T12:22:11+00:00

commit 4f134b89a24b965991e7c345b9a4591821f7c2a6 upstream. Lilith >_> and Claudio Bozzato of Cisco Talos security team reported that collect_syscall() improperly casts the syscall registers to 64-bit values leaking the uninitialized last 24 bytes on 32-bit platforms, that are visible in /proc/self/syscall. The cause is that info->data.args are u64 while syscall_get_arguments() uses longs, as hinted by the bogus pointer cast in the function. Let's just proceed like the other call places, by retrieving the registers into an array of longs before assigning them to the caller's array. This was successfully tested on x86_64, i386 and ppc32. Reference: CVE-2020-28588, TALOS-2020-1211 Fixes: 631b7abacd02 ("ptrace: Remove maxargs from task_current_syscall()") Cc: Greg KH Reviewed-by: Kees Cook Tested-by: Michael Ellerman (ppc32) Signed-off-by: Willy Tarreau Reviewed-by: Thomas Gleixner Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

lib/strncpy_from_user.c: Mask out bytes after NUL terminator.

2020-11-24T12:39:05+00:00

[ Upstream commit 6fa6d28051e9fcaa1570e69648ea13a353a5d218 ] do_strncpy_from_user() may copy some extra bytes after the NUL terminator into the destination buffer. This usually does not matter for normal string operations. However, when BPF programs key BPF maps with strings, this matters a lot. A BPF program may read strings from user memory by calling the bpf_probe_read_user_str() helper which eventually calls do_strncpy_from_user(). The program can then key a map with the destination buffer. BPF map keys are fixed-width and string-agnostic, meaning that map keys are treated as a set of bytes. The issue is when do_strncpy_from_user() overcopies bytes after the NUL terminator, it can result in seemingly identical strings occupying multiple slots in a BPF map. This behavior is subtle and totally unexpected by the user. This commit masks out the bytes following the NUL while preserving long-sized stride in the fast path. Fixes: 6ae08ae3dea2 ("bpf: Add probe_read_{user, kernel} and probe_read_{user, kernel}_str helpers") Signed-off-by: Daniel Xu Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/21efc982b3e9f2f7b0379eed642294caaa0c27a7.1605642949.git.dxu@dxuuu.xyz Signed-off-by: Sasha Levin

lib/crc32test: remove extra local_irq_disable/enable

2020-11-10T11:39:00+00:00

commit aa4e460f0976351fddd2f5ac6e08b74320c277a1 upstream. Commit 4d004099a668 ("lockdep: Fix lockdep recursion") uncovered the following issue in lib/crc32test reported on s390: BUG: using __this_cpu_read() in preemptible [00000000] code: swapper/0/1 caller is lockdep_hardirqs_on_prepare+0x48/0x270 CPU: 6 PID: 1 Comm: swapper/0 Not tainted 5.9.0-next-20201015-15164-g03d992bd2de6 #19 Hardware name: IBM 3906 M04 704 (LPAR) Call Trace: lockdep_hardirqs_on_prepare+0x48/0x270 trace_hardirqs_on+0x9c/0x1b8 crc32_test.isra.0+0x170/0x1c0 crc32test_init+0x1c/0x40 do_one_initcall+0x40/0x130 do_initcalls+0x126/0x150 kernel_init_freeable+0x1f6/0x230 kernel_init+0x22/0x150 ret_from_fork+0x24/0x2c no locks held by swapper/0/1. Remove extra local_irq_disable/local_irq_enable helpers calls. Fixes: 5fb7f87408f1 ("lib: add module support to crc32 tests") Signed-off-by: Vasily Gorbik Signed-off-by: Andrew Morton Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Greg Kroah-Hartman Link: https://lkml.kernel.org/r/patch.git-4369da00c06e.your-ad-here.call-01602859837-ext-1679@work.hours Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

Fonts: Replace discarded const qualifier

2020-11-10T11:38:59+00:00

commit 9522750c66c689b739e151fcdf895420dc81efc0 upstream. Commit 6735b4632def ("Fonts: Support FONT_EXTRA_WORDS macros for built-in fonts") introduced the following error when building rpc_defconfig (only this build appears to be affected): `acorndata_8x8' referenced in section `.text' of arch/arm/boot/compressed/ll_char_wr.o: defined in discarded section `.data' of arch/arm/boot/compressed/font.o `acorndata_8x8' referenced in section `.data.rel.ro' of arch/arm/boot/compressed/font.o: defined in discarded section `.data' of arch/arm/boot/compressed/font.o make[3]: *** [/scratch/linux/arch/arm/boot/compressed/Makefile:191: arch/arm/boot/compressed/vmlinux] Error 1 make[2]: *** [/scratch/linux/arch/arm/boot/Makefile:61: arch/arm/boot/compressed/vmlinux] Error 2 make[1]: *** [/scratch/linux/arch/arm/Makefile:317: zImage] Error 2 The .data section is discarded at link time. Reinstating acorndata_8x8 as const ensures it is still available after linking. Do the same for the other 12 built-in fonts as well, for consistency purposes. Cc: Cc: Russell King Reviewed-by: Greg Kroah-Hartman Fixes: 6735b4632def ("Fonts: Support FONT_EXTRA_WORDS macros for built-in fonts") Signed-off-by: Lee Jones Co-developed-by: Peilin Ye Signed-off-by: Peilin Ye Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20201102183242.2031659-1-yepeilin.cs@gmail.com Signed-off-by: Greg Kroah-Hartman

sgl_alloc_order: fix memory leak

2020-11-05T10:51:30+00:00

[ Upstream commit b2a182a40278bc5849730e66bca01a762188ed86 ] sgl_alloc_order() can fail when 'length' is large on a memory constrained system. When order > 0 it will potentially be making several multi-page allocations with the later ones more likely to fail than the earlier one. So it is important that sgl_alloc_order() frees up any pages it has obtained before returning NULL. In the case when order > 0 it calls the wrong free page function and leaks. In testing the leak was sufficient to bring down my 8 GiB laptop with OOM. Reviewed-by: Bart Van Assche Signed-off-by: Douglas Gilbert Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()

2020-11-04T17:09:05+00:00

commit ec6347bb43395cb92126788a1a5b25302543f815 upstream. In reaction to a proposal to introduce a memcpy_mcsafe_fast() implementation Linus points out that memcpy_mcsafe() is poorly named relative to communicating the scope of the interface. Specifically what addresses are valid to pass as source, destination, and what faults / exceptions are handled. Of particular concern is that even though x86 might be able to handle the semantics of copy_mc_to_user() with its common copy_user_generic() implementation other archs likely need / want an explicit path for this case: On Fri, May 1, 2020 at 11:28 AM Linus Torvalds wrote: > > On Thu, Apr 30, 2020 at 6:21 PM Dan Williams wrote: > > > > However now I see that copy_user_generic() works for the wrong reason. > > It works because the exception on the source address due to poison > > looks no different than a write fault on the user address to the > > caller, it's still just a short copy. So it makes copy_to_user() work > > for the wrong reason relative to the name. > > Right. > > And it won't work that way on other architectures. On x86, we have a > generic function that can take faults on either side, and we use it > for both cases (and for the "in_user" case too), but that's an > artifact of the architecture oddity. > > In fact, it's probably wrong even on x86 - because it can hide bugs - > but writing those things is painful enough that everybody prefers > having just one function. Replace a single top-level memcpy_mcsafe() with either copy_mc_to_user(), or copy_mc_to_kernel(). Introduce an x86 copy_mc_fragile() name as the rename for the low-level x86 implementation formerly named memcpy_mcsafe(). It is used as the slow / careful backend that is supplanted by a fast copy_mc_generic() in a follow-on patch. One side-effect of this reorganization is that separating copy_mc_64.S to its own file means that perf no longer needs to track dependencies for its memcpy_64.S benchmarks. [ bp: Massage a bit. ] Signed-off-by: Dan Williams Signed-off-by: Borislav Petkov Reviewed-by: Tony Luck Acked-by: Michael Ellerman Cc: Link: http://lore.kernel.org/r/CAHk-=wjSqtXAqfUJxFtWNwmguFASTgB0dz1dT3V-78Quiezqbg@mail.gmail.com Link: https://lkml.kernel.org/r/160195561680.2163339.11574962055305783722.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Greg Kroah-Hartman

Revert "x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()"

2020-11-04T17:08:28+00:00

This reverts commit a85748ed9eb70108f9605558f2754ca94ee91401 which is commit ec6347bb43395cb92126788a1a5b25302543f815 upstream. We had a mistake when merging a later patch in this series due to some file movements, so revert this change for now, as we will add it back in a later commit. Signed-off-by: Greg Kroah-Hartman

x86, powerpc: Rename memcpy_mcsafe() to copy_mc_to_{user, kernel}()

2020-11-01T11:47:03+00:00

random32: make prandom_u32() output unpredictable

2020-10-29T09:12:07+00:00

[ Upstream commit c51f8f88d705e06bd696d7510aff22b33eb8e638 ] Non-cryptographic PRNGs may have great statistical properties, but are usually trivially predictable to someone who knows the algorithm, given a small sample of their output. An LFSR like prandom_u32() is particularly simple, even if the sample is widely scattered bits. It turns out the network stack uses prandom_u32() for some things like random port numbers which it would prefer are *not* trivially predictable. Predictability led to a practical DNS spoofing attack. Oops. This patch replaces the LFSR with a homebrew cryptographic PRNG based on the SipHash round function, which is in turn seeded with 128 bits of strong random key. (The authors of SipHash have *not* been consulted about this abuse of their algorithm.) Speed is prioritized over security; attacks are rare, while performance is always wanted. Replacing all callers of prandom_u32() is the quick fix. Whether to reinstate a weaker PRNG for uses which can tolerate it is an open question. Commit f227e3ec3b5c ("random32: update the net random state on interrupt and activity") was an earlier attempt at a solution. This patch replaces it. Reported-by: Amit Klein Cc: Willy Tarreau Cc: Eric Dumazet Cc: "Jason A. Donenfeld" Cc: Andy Lutomirski Cc: Kees Cook Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Linus Torvalds Cc: tytso@mit.edu Cc: Florian Westphal Cc: Marc Plumb Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity") Signed-off-by: George Spelvin Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/ [ willy: partial reversal of f227e3ec3b5c; moved SIPROUND definitions to prandom.h for later use; merged George's prandom_seed() proposal; inlined siprand_u32(); replaced the net_rand_state[] array with 4 members to fix a build issue; cosmetic cleanups to make checkpatch happy; fixed RANDOM32_SELFTEST build ] Signed-off-by: Willy Tarreau Signed-off-by: Sasha Levin