kernel/linux.git, branch v4.19.144

Linux 4.19.144

2020-09-09T17:04:32+00:00

Tested-by: Shuah Khan Tested-by: Jon Hunter Tested-by: Linux Kernel Functional Testing Tested-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

net: usb: Fix uninit-was-stored issue in asix_read_phy_addr()

2020-09-09T17:04:32+00:00

commit a092b7233f0e000cc6f2c71a49e2ecc6f917a5fc upstream. The buffer size is 2 Bytes and we expect to receive the same amount of data. But sometimes we receive less data and run into uninit-was-stored issue upon read. Hence modify the error check on the return value to match with the buffer size as a prevention. Reported-and-tested by: syzbot+a7e220df5a81d1ab400e@syzkaller.appspotmail.com Signed-off-by: Himadri Pandya Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

cfg80211: regulatory: reject invalid hints

2020-09-09T17:04:32+00:00

commit 47caf685a6854593348f216e0b489b71c10cbe03 upstream. Reject invalid hints early in order to not cause a kernel WARN later if they're restored to or similar. Reported-by: syzbot+d451401ffd00a60677ee@syzkaller.appspotmail.com Link: https://syzkaller.appspot.com/bug?extid=d451401ffd00a60677ee Link: https://lore.kernel.org/r/20200819084648.13956-1-johannes@sipsolutions.net Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman

mm/hugetlb: fix a race between hugetlb sysctl handlers

2020-09-09T17:04:32+00:00

commit 17743798d81238ab13050e8e2833699b54e15467 upstream. There is a race between the assignment of `table->data` and write value to the pointer of `table->data` in the __do_proc_doulongvec_minmax() on the other thread. CPU0: CPU1: proc_sys_write hugetlb_sysctl_handler proc_sys_call_handler hugetlb_sysctl_handler_common hugetlb_sysctl_handler table->data = &tmp; hugetlb_sysctl_handler_common table->data = &tmp; proc_doulongvec_minmax do_proc_doulongvec_minmax sysctl_head_finish __do_proc_doulongvec_minmax unuse_table i = table->data; *i = val; // corrupt CPU1's stack Fix this by duplicating the `table`, and only update the duplicate of it. And introduce a helper of proc_hugetlb_doulongvec_minmax() to simplify the code. The following oops was seen: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page Code: Bad RIP value. ... Call Trace: ? set_max_huge_pages+0x3da/0x4f0 ? alloc_pool_huge_page+0x150/0x150 ? proc_doulongvec_minmax+0x46/0x60 ? hugetlb_sysctl_handler_common+0x1c7/0x200 ? nr_hugepages_store+0x20/0x20 ? copy_fd_bitmaps+0x170/0x170 ? hugetlb_sysctl_handler+0x1e/0x20 ? proc_sys_call_handler+0x2f1/0x300 ? unregister_sysctl_table+0xb0/0xb0 ? __fd_install+0x78/0x100 ? proc_sys_write+0x14/0x20 ? __vfs_write+0x4d/0x90 ? vfs_write+0xef/0x240 ? ksys_write+0xc0/0x160 ? __ia32_sys_read+0x50/0x50 ? __close_fd+0x129/0x150 ? __x64_sys_write+0x43/0x50 ? do_syscall_64+0x6c/0x200 ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 Fixes: e5ff215941d5 ("hugetlb: multiple hstates for multiple page sizes") Signed-off-by: Muchun Song Signed-off-by: Andrew Morton Reviewed-by: Mike Kravetz Cc: Andi Kleen Link: http://lkml.kernel.org/r/20200828031146.43035-1-songmuchun@bytedance.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

checkpatch: fix the usage of capture group ( ... )

2020-09-09T17:04:32+00:00

commit 13e45417cedbfc44b1926124b1846f5ee8c6ba4a upstream. The usage of "capture group (...)" in the immediate condition after `&&` results in `$1` being uninitialized. This issues a warning "Use of uninitialized value $1 in regexp compilation at ./scripts/checkpatch.pl line 2638". I noticed this bug while running checkpatch on the set of commits from v5.7 to v5.8-rc1 of the kernel on the commits with a diff content in their commit message. This bug was introduced in the script by commit e518e9a59ec3 ("checkpatch: emit an error when there's a diff in a changelog"). It has been in the script since then. The author intended to store the match made by capture group in variable `$1`. This should have contained the name of the file as `[\w/]+` matched. However, this couldn't be accomplished due to usage of capture group and `$1` in the same regular expression. Fix this by placing the capture group in the condition before `&&`. Thus, `$1` can be initialized to the text that capture group matches thereby setting it to the desired and required value. Fixes: e518e9a59ec3 ("checkpatch: emit an error when there's a diff in a changelog") Signed-off-by: Mrinal Pandey Signed-off-by: Andrew Morton Tested-by: Lukas Bulwahn Reviewed-by: Lukas Bulwahn Cc: Joe Perches Link: https://lkml.kernel.org/r/20200714032352.f476hanaj2dlmiot@mrinalpandey Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

vfio/pci: Fix SR-IOV VF handling with MMIO blocking

2020-09-09T17:04:32+00:00

commit ebfa440ce38b7e2e04c3124aa89c8a9f4094cf21 upstream. SR-IOV VFs do not implement the memory enable bit of the command register, therefore this bit is not set in config space after pci_enable_device(). This leads to an unintended difference between PF and VF in hand-off state to the user. We can correct this by setting the initial value of the memory enable bit in our virtualized config space. There's really no need however to ever fault a user on a VF though as this would only indicate an error in the user's management of the enable bit, versus a PF where the same access could trigger hardware faults. Fixes: abafbc551fdd ("vfio-pci: Invalidate mmaps and block MMIO access on disabled memory") Signed-off-by: Alex Williamson Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Set HCR_EL2.PTW to prevent AT taking synchronous exception

2020-09-09T17:04:32+00:00

commit 71a7f8cb1ca4ca7214a700b1243626759b6c11d4 upstream. AT instructions do a translation table walk and return the result, or the fault in PAR_EL1. KVM uses these to find the IPA when the value is not provided by the CPU in HPFAR_EL1. If a translation table walk causes an external abort it is taken as an exception, even if it was due to an AT instruction. (DDI0487F.a's D5.2.11 "Synchronous faults generated by address translation instructions") While we previously made KVM resilient to exceptions taken due to AT instructions, the device access causes mismatched attributes, and may occur speculatively. Prevent this, by forbidding a walk through memory described as device at stage2. Now such AT instructions will report a stage2 fault. Such a fault will cause KVM to restart the guest. If the AT instructions always walk the page tables, but guest execution uses the translation cached in the TLB, the guest can't make forward progress until the TLB entry is evicted. This isn't a problem, as since commit 5dcd0fdbb492 ("KVM: arm64: Defer guest entry when an asynchronous exception is pending"), KVM will return to the host to process IRQs allowing the rest of the system to keep running. Cc: stable@vger.kernel.org # v4.19 Signed-off-by: James Morse Reviewed-by: Marc Zyngier Signed-off-by: Catalin Marinas Signed-off-by: Andre Przywara Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Survive synchronous exceptions caused by AT instructions

2020-09-09T17:04:32+00:00

commit 88a84ccccb3966bcc3f309cdb76092a9892c0260 upstream. KVM doesn't expect any synchronous exceptions when executing, any such exception leads to a panic(). AT instructions access the guest page tables, and can cause a synchronous external abort to be taken. The arm-arm is unclear on what should happen if the guest has configured the hardware update of the access-flag, and a memory type in TCR_EL1 that does not support atomic operations. B2.2.6 "Possible implementation restrictions on using atomic instructions" from DDI0487F.a lists synchronous external abort as a possible behaviour of atomic instructions that target memory that isn't writeback cacheable, but the page table walker may behave differently. Make KVM robust to synchronous exceptions caused by AT instructions. Add a get_user() style helper for AT instructions that returns -EFAULT if an exception was generated. While KVM's version of the exception table mixes synchronous and asynchronous exceptions, only one of these can occur at each location. Re-enter the guest when the AT instructions take an exception on the assumption the guest will take the same exception. This isn't guaranteed to make forward progress, as the AT instructions may always walk the page tables, but guest execution may use the translation cached in the TLB. This isn't a problem, as since commit 5dcd0fdbb492 ("KVM: arm64: Defer guest entry when an asynchronous exception is pending"), KVM will return to the host to process IRQs allowing the rest of the system to keep running. Cc: stable@vger.kernel.org # v4.19 Signed-off-by: James Morse Reviewed-by: Marc Zyngier Signed-off-by: Catalin Marinas Signed-off-by: Andre Przywara Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Defer guest entry when an asynchronous exception is pending

2020-09-09T17:04:31+00:00

commit 5dcd0fdbb492d49dac6bf21c436dfcb5ded0a895 upstream. SError that occur during world-switch's entry to the guest will be accounted to the guest, as the exception is masked until we enter the guest... but we want to attribute the SError as precisely as possible. Reading DISR_EL1 before guest entry requires free registers, and using ESB+DISR_EL1 to consume and read back the ESR would leave KVM holding a host SError... We would rather leave the SError pending and let the host take it once we exit world-switch. To do this, we need to defer guest-entry if an SError is pending. Read the ISR to see if SError (or an IRQ) is pending. If so fake an exit. Place this check between __guest_enter()'s save of the host registers, and restore of the guest's. SError that occur between here and the eret into the guest must have affected the guest's registers, which we can naturally attribute to the guest. The dsb is needed to ensure any previous writes have been done before we read ISR_EL1. On systems without the v8.2 RAS extensions this doesn't give us anything as we can't contain errors, and the ESR bits to describe the severity are all implementation-defined. Replace this with a nop for these systems. Cc: stable@vger.kernel.org # v4.19 Signed-off-by: James Morse Signed-off-by: Marc Zyngier Signed-off-by: Andre Przywara Signed-off-by: Greg Kroah-Hartman

KVM: arm64: Add kvm_extable for vaxorcism code

2020-09-09T17:04:31+00:00

commit e9ee186bb735bfc17fa81dbc9aebf268aee5b41e upstream. KVM has a one instruction window where it will allow an SError exception to be consumed by the hypervisor without treating it as a hypervisor bug. This is used to consume asynchronous external abort that were caused by the guest. As we are about to add another location that survives unexpected exceptions, generalise this code to make it behave like the host's extable. KVM's version has to be mapped to EL2 to be accessible on nVHE systems. The SError vaxorcism code is a one instruction window, so has two entries in the extable. Because the KVM code is copied for VHE and nVHE, we end up with four entries, half of which correspond with code that isn't mapped. Signed-off-by: James Morse Reviewed-by: Marc Zyngier Signed-off-by: Catalin Marinas Signed-off-by: Andre Przywara Signed-off-by: Greg Kroah-Hartman