- 12 Nov, 2019 40 commits
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Greg Kroah-Hartman authored
BugLink: https://bugs.launchpad.net/bugs/1852110Signed-off-by:
Connor Kuehl <connor.kuehl@canonical.com> Signed-off-by:
Khalid Elmously <khalid.elmously@canonical.com>
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zhangyi (F) authored
BugLink: https://bugs.launchpad.net/bugs/1852110 During backport 1e2e547a "do d_instantiate/unlock_new_inode combinations safely", there was a error instantiating sequence of attaching dentry to inode and calling security_d_instantiate(). Before commit ce23e640 "->getxattr(): pass dentry and inode as separate arguments" and b9680917 "security_d_instantiate(): move to the point prior to attaching dentry to inode", security_d_instantiate() should be called beind __d_instantiate(), otherwise it will trigger below problem when CONFIG_SECURITY_SMACK on ext4 was enabled because d_inode(dentry) used by ->getxattr() is NULL before __d_instantiate() instantiate inode. [ 31.858026] BUG: unable to handle kernel paging request at ffffffffffffff70 ... [ 31.882024] Call Trace: [ 31.882378] [<ffffffffa347f75c>] ext4_xattr_get+0x8c/0x3e0 [ 31.883195] [<ffffffffa3489454>] ext4_xattr_security_get+0x24/0x40 [ 31.884086] [<ffffffffa336a56b>] generic_getxattr+0x5b/0x90 [ 31.884907] [<ffffffffa3700514>] smk_fetch+0xb4/0x150 [ 31.885634] [<ffffffffa3700772>] smack_d_instantiate+0x1c2/0x550 [ 31.886508] [<ffffffffa36f9a5a>] security_d_instantiate+0x3a/0x80 [ 31.887389] [<ffffffffa3353b26>] d_instantiate_new+0x36/0x130 [ 31.888223] [<ffffffffa342b1ef>] ext4_mkdir+0x4af/0x6a0 [ 31.888928] [<ffffffffa3343470>] vfs_mkdir+0x100/0x280 [ 31.889536] [<ffffffffa334b086>] SyS_mkdir+0xb6/0x170 [ 31.890255] [<ffffffffa307c855>] ? trace_do_page_fault+0x95/0x2b0 [ 31.891134] [<ffffffffa3c5e078>] entry_SYSCALL_64_fastpath+0x18/0x73 Cc: <stable@vger.kernel.org> # 3.16, 4.4 Signed-off-by:
zhangyi (F) <yi.zhang@huawei.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
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Petr Vorel authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Fix backport of commit f18ddc13 upstream. Update backport to change ENOTSUPP to EOPNOTSUPP in alarm_timer_{del,set}(), which were removed in f2c45807 in v4.13-rc1. Fixes: c22df8ea7c5831d6fdca2f6f136f0d32d7064ff9 Signed-off-by:
Petr Vorel <pvorel@suse.cz> Acked-by:
Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by:
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Russell King authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit d6951f58 upstream. The intention in the previous patch was to only place the processor tables in the .rodata section if big.Little was being built and we wanted the branch target hardening, but instead (due to the way it was tested) it ended up always placing the tables into the .rodata section. Although harmless, let's correct this anyway. Fixes: 3a4d0c21 ("ARM: ensure that processor vtables is not lost after boot") Signed-off-by:
Russell King <rmk+kernel@armlinux.org.uk> Signed-off-by:
David A. Long <dave.long@linaro.org> Reviewed-by:
Julien Thierry <julien.thierry@arm.com> Signed-off-by:
Sasha Levin <sashal@kernel.org> Signed-off-by:
Ard Biesheuvel <ardb@kernel.org> Signed-off-by:
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Russell King authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit 3a4d0c21 upstream. Marek Szyprowski reported problems with CPU hotplug in current kernels. This was tracked down to the processor vtables being located in an init section, and therefore discarded after kernel boot, despite being required after boot to properly initialise the non-boot CPUs. Arrange for these tables to end up in .rodata when required. Reported-by:
Marek Szyprowski <m.szyprowski@samsung.com> Tested-by:
Krzysztof Kozlowski <krzk@kernel.org> Fixes: 383fb3ee ("ARM: spectre-v2: per-CPU vtables to work around big.Little systems") Signed-off-by:
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Russell King authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit 383fb3ee upstream. In big.Little systems, some CPUs require the Spectre workarounds in paths such as the context switch, but other CPUs do not. In order to handle these differences, we need per-CPU vtables. We are unable to use the kernel's per-CPU variables to support this as per-CPU is not initialised at times when we need access to the vtables, so we have to use an array indexed by logical CPU number. We use an array-of-pointers to avoid having function pointers in the kernel's read/write .data section. Note: Added include of linux/slab.h in arch/arm/smp.c. Reviewed-by:
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Russell King authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit e209950f upstream. Allow the way we access members of the processor vtable to be changed at compile time. We will need to move to per-CPU vtables to fix the Spectre variant 2 issues on big.Little systems. However, we have a couple of calls that do not need the vtable treatment, and indeed cause a kernel warning due to the (later) use of smp_processor_id(), so also introduce the PROC_TABLE macro for these which always use CPU 0's function pointers. Reviewed-by:
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Russell King authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit 945aceb1 upstream. Call the per-processor type check_bugs() method in the same way as we do other per-processor functions - move the "processor." detail into proc-fns.h. Reviewed-by:
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Russell King authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit 65987a85 upstream. Split out the lookup of the processor type and associated error handling from the rest of setup_processor() - we will need to use this in the secondary CPU bringup path for big.Little Spectre variant 2 mitigation. Reviewed-by:
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Russell King authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit 899a42f8 upstream. Move lookup_processor_type() out of the __init section so it is callable from (eg) the secondary startup code during hotplug. Reviewed-by:
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Julien Thierry authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit 5df7a99b upstream. In vfp_preserve_user_clear_hwstate, ufp_exc->fpinst2 gets assigned to itself. It should actually be hwstate->fpinst2 that gets assigned to the ufp_exc field. Fixes commit 3aa2df6e ("ARM: 8791/1: vfp: use __copy_to_user() when saving VFP state"). Reported-by:
David Binderman <dcb314@hotmail.com> Signed-off-by:
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Julien Thierry authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit afaf6838 upstream. Introduce C and asm helpers to sanitize user address, taking the address range they target into account. Use asm helper for existing sanitization in __copy_from_user(). Signed-off-by:
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Julien Thierry authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit e3aa6243 upstream. When Spectre mitigation is required, __put_user() needs to include check_uaccess. This is already the case for put_user(), so just make __put_user() an alias of put_user(). Signed-off-by:
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Julien Thierry authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit 621afc67 upstream. A mispredicted conditional call to set_fs could result in the wrong addr_limit being forwarded under speculation to a subsequent access_ok check, potentially forming part of a spectre-v1 attack using uaccess routines. This patch prevents this forwarding from taking place, but putting heavy barriers in set_fs after writing the addr_limit. Porting commit c2f0ad4f ("arm64: uaccess: Prevent speculative use of the current addr_limit"). Signed-off-by:
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Julien Thierry authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit 18ea66bd upstream. With Spectre-v1.1 mitigations, __put_user_error is pointless. In an attempt to remove it, replace its references in frame setups with __put_user. Signed-off-by:
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Julien Thierry authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit 31950890 upstream. Copy events to user using __copy_to_user() rather than copy members of individually with __put_user_error(). This has the benefit of disabling/enabling PAN once per event intead of once per event member. Signed-off-by:
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Julien Thierry authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit 3aa2df6e upstream. Use __copy_to_user() rather than __put_user_error() for individual members when saving VFP state. This has the benefit of disabling/enabling PAN once per copied struct intead of once per write. Signed-off-by:
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Julien Thierry authored
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit 5ca451cf upstream. When saving the ARM integer registers, use __copy_to_user() to copy them into user signal frame, rather than __put_user_error(). This has the benefit of disabling/enabling PAN once for the whole copy intead of once per write. Signed-off-by:
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Russell King authored
BugLink: https://bugs.launchpad.net/bugs/1852110 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:
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Russell King authored
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 Commit a78d1565 upstream. Add assembly and C macros for the new CSDB instruction. Signed-off-by:
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Russell King authored
BugLink: https://bugs.launchpad.net/bugs/1852110 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:
Marc Zyngier <marc.zyngier@arm.com> Signed-off-by:
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Russell King authored
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 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:
Florian Fainelli <f.fainelli@gmail.com> Boot-tested-by:
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Russell King authored
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 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
BugLink: https://bugs.launchpad.net/bugs/1852110 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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Marc Zyngier authored
BugLink: https://bugs.launchpad.net/bugs/1852110 [ Upstream commit 755a8bf5 ] If someone has the silly idea to write something along those lines: extern u64 foo(void); void bar(struct arm_smccc_res *res) { arm_smccc_1_1_smc(0xbad, foo(), res); } they are in for a surprise, as this gets compiled as: 0000000000000588 <bar>: 588: a9be7bfd stp x29, x30, [sp, #-32]! 58c: 910003fd mov x29, sp 590: f9000bf3 str x19, [sp, #16] 594: aa0003f3 mov x19, x0 598: aa1e03e0 mov x0, x30 59c: 94000000 bl 0 <_mcount> 5a0: 94000000 bl 0 <foo> 5a4: aa0003e1 mov x1, x0 5a8: d4000003 smc #0x0 5ac: b4000073 cbz x19, 5b8 <bar+0x30> 5b0: a9000660 stp x0, x1, [x19] 5b4: a9010e62 stp x2, x3, [x19, #16] 5b8: f9400bf3 ldr x19, [sp, #16] 5bc: a8c27bfd ldp x29, x30, [sp], #32 5c0: d65f03c0 ret 5c4: d503201f nop The call to foo "overwrites" the x0 register for the return value, and we end up calling the wrong secure service. A solution is to evaluate all the parameters before assigning anything to specific registers, leading to the expected result: 0000000000000588 <bar>: 588: a9be7bfd stp x29, x30, [sp, #-32]! 58c: 910003fd mov x29, sp 590: f9000bf3 str x19, [sp, #16] 594: aa0003f3 mov x19, x0 598: aa1e03e0 mov x0, x30 59c: 94000000 bl 0 <_mcount> 5a0: 94000000 bl 0 <foo> 5a4: aa0003e1 mov x1, x0 5a8: d28175a0 mov x0, #0xbad 5ac: d4000003 smc #0x0 5b0: b4000073 cbz x19, 5bc <bar+0x34> 5b4: a9000660 stp x0, x1, [x19] 5b8: a9010e62 stp x2, x3, [x19, #16] 5bc: f9400bf3 ldr x19, [sp, #16] 5c0: a8c27bfd ldp x29, x30, [sp], #32 5c4: d65f03c0 ret Reported-by:
Julien Grall <julien.grall@arm.com> Signed-off-by:
Will Deacon <will.deacon@arm.com> Signed-off-by:
Sasha Levin <alexander.levin@microsoft.com> Signed-off-by:
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Marc Zyngier authored
BugLink: https://bugs.launchpad.net/bugs/1852110 [ Upstream commit 1d8f5747 ] An unfortunate consequence of having a strong typing for the input values to the SMC call is that it also affects the type of the return values, limiting r0 to 32 bits and r{1,2,3} to whatever was passed as an input. Let's turn everything into "unsigned long", which satisfies the requirements of both architectures, and allows for the full range of return values. Reported-by:
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Marc Zyngier authored
BugLink: https://bugs.launchpad.net/bugs/1852110 commit eff0e9e1 upstream. We've so far used the PSCI return codes for SMCCC because they were extremely similar. But with the new ARM DEN 0070A specification, "NOT_REQUIRED" (-2) is clashing with PSCI's "PSCI_RET_INVALID_PARAMS". Let's bite the bullet and add SMCCC specific return codes. Users can be repainted as and when required. Acked-by:
Catalin Marinas <catalin.marinas@arm.com> Signed-off-by:
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