commit 9c6a73c758 upstream.
With LFENCE now a serializing instruction, use LFENCE_RDTSC in preference
to MFENCE_RDTSC. However, since the kernel could be running under a
hypervisor that does not support writing that MSR, read the MSR back and
verify that the bit has been set successfully. If the MSR can be read
and the bit is set, then set the LFENCE_RDTSC feature, otherwise set the
MFENCE_RDTSC feature.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/20180108220932.12580.52458.stgit@tlendack-t1.amdoffice.net
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit e4d0e84e49 upstream.
To aid in speculation control, make LFENCE a serializing instruction
since it has less overhead than MFENCE. This is done by setting bit 1
of MSR 0xc0011029 (DE_CFG). Some families that support LFENCE do not
have this MSR. For these families, the LFENCE instruction is already
serializing.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/20180108220921.12580.71694.stgit@tlendack-t1.amdoffice.net
[bwh: Backported to 3.16: adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 612e8e9350 upstream.
The alternatives code checks only the first byte whether it is a NOP, but
with NOPs in front of the payload and having actual instructions after it
breaks the "optimized' test.
Make sure to scan all bytes before deciding to optimize the NOPs in there.
Reported-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/20180110112815.mgciyf5acwacphkq@pd.tnic
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 66c117d7fa upstream.
Richard reported the following crash:
[ 0.036000] BUG: unable to handle kernel paging request at 55501e06
[ 0.036000] IP: [<c0aae48b>] common_interrupt+0xb/0x38
[ 0.036000] Call Trace:
[ 0.036000] [<c0409c80>] ? add_nops+0x90/0xa0
[ 0.036000] [<c040a054>] apply_alternatives+0x274/0x630
Chuck decoded:
" 0: 8d 90 90 83 04 24 lea 0x24048390(%eax),%edx
6: 80 fc 0f cmp $0xf,%ah
9: a8 0f test $0xf,%al
>> b: a0 06 1e 50 55 mov 0x55501e06,%al
10: 57 push %edi
11: 56 push %esi
Interrupt 0x30 occurred while the alternatives code was replacing the
initial 0x90,0x90,0x90 NOPs (from the ASM_CLAC macro) with the
optimized version, 0x8d,0x76,0x00. Only the first byte has been
replaced so far, and it makes a mess out of the insn decoding."
optimize_nops() is buggy in two aspects:
- It's not disabling interrupts across the modification
- It's lacking a sync_core() call
Add both.
Fixes: 4fd4b6e553 'x86/alternatives: Use optimized NOPs for padding'
Reported-and-tested-by: "Richard W.M. Jones" <rjones@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard W.M. Jones <rjones@redhat.com>
Cc: Chuck Ebbert <cebbert.lkml@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1509031232340.15006@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit dbe4058a6a upstream.
Quentin caught a corner case with the generation of instruction
padding in the ALTERNATIVE_2 macro: if len(orig_insn) <
len(alt1) < len(alt2), then not enough padding gets added and
that is not good(tm) as we could overwrite the beginning of the
next instruction.
Luckily, at the time of this writing, we don't have
ALTERNATIVE_2() invocations which have that problem and even if
we did, a simple fix would be to prepend the instructions with
enough prefixes so that that corner case doesn't happen.
However, best it would be if we fixed it properly. See below for
a simple, abstracted example of what we're doing.
So what we ended up doing is, we compute the
max(len(alt1), len(alt2)) - len(orig_insn)
and feed that value to the .skip gas directive. The max() cannot
have conditionals due to gas limitations, thus the fancy integer
math.
With this patch, all ALTERNATIVE_2 sites get padded correctly;
generating obscure test cases pass too:
#define alt_max_short(a, b) ((a) ^ (((a) ^ (b)) & -(-((a) < (b)))))
#define gen_skip(orig, alt1, alt2, marker) \
.skip -((alt_max_short(alt1, alt2) - (orig)) > 0) * \
(alt_max_short(alt1, alt2) - (orig)),marker
.pushsection .text, "ax"
.globl main
main:
gen_skip(1, 2, 4, 0x09)
gen_skip(4, 1, 2, 0x10)
...
.popsection
Thanks to Quentin for catching it and double-checking the fix!
Reported-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150404133443.GE21152@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 69df353ff3 upstream.
Take a look at the first instruction byte before optimizing the NOP -
there might be something else there already, like the ALTERNATIVE_2()
in rdtsc_barrier() which NOPs out on AMD even though we just
patched in an MFENCE.
This happens because the alternatives sees X86_FEATURE_MFENCE_RDTSC,
AMD CPUs set it, we patch in the MFENCE and right afterwards it sees
X86_FEATURE_LFENCE_RDTSC which AMD CPUs don't set and we blindly
optimize the NOP.
Checking whether at least the first byte is 0x90 prevents that.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1428181662-18020-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 61dc0f555b upstream.
Implement the CPU vulnerabilty show functions for meltdown, spectre_v1 and
spectre_v2.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180107214913.177414879@linutronix.de
[bwh: Backported to 3.16:
- Meltdown mitigation feature flag is KAISER
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 87590ce6e3 upstream.
As the meltdown/spectre problem affects several CPU architectures, it makes
sense to have common way to express whether a system is affected by a
particular vulnerability or not. If affected the way to express the
mitigation should be common as well.
Create /sys/devices/system/cpu/vulnerabilities folder and files for
meltdown, spectre_v1 and spectre_v2.
Allow architectures to override the show function.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Link: https://lkml.kernel.org/r/20180107214913.096657732@linutronix.de
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 62a67e123e upstream.
Should be easier when following boot paths. It probably is a left over
from the x86 unification eons ago.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20161024173844.23038-3-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16:
- Add #ifdef around check_fpu(), which is not used on x86_64
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 99c6fa2511 upstream.
Add the bug bits for spectre v1/2 and force them unconditionally for all
cpus.
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/1515239374-23361-2-git-send-email-dwmw@amazon.co.uk
[bwh: Backported to 3.16: assign the first available bug numbers]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit de791821c2 upstream.
Use the name associated with the particular attack which needs page table
isolation for mitigation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk>
Cc: Jiri Koshina <jikos@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andi Lutomirski <luto@amacapital.net>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Turner <pjt@google.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Greg KH <gregkh@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801051525300.1724@nanos
[bwh: Backported to 3.16: bug number is different]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 694d99d409 upstream.
AMD processors are not subject to the types of attacks that the kernel
page table isolation feature protects against. The AMD microarchitecture
does not allow memory references, including speculative references, that
access higher privileged data when running in a lesser privileged mode
when that access would result in a page fault.
Disable page table isolation by default on AMD processors by not setting
the X86_BUG_CPU_INSECURE feature, which controls whether X86_FEATURE_PTI
is set.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20171227054354.20369.94587.stgit@tlendack-t1.amdoffice.net
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit a89f040fa3 upstream.
Many x86 CPUs leak information to user space due to missing isolation of
user space and kernel space page tables. There are many well documented
ways to exploit that.
The upcoming software migitation of isolating the user and kernel space
page tables needs a misfeature flag so code can be made runtime
conditional.
Add the BUG bits which indicates that the CPU is affected and add a feature
bit which indicates that the software migitation is enabled.
Assume for now that _ALL_ x86 CPUs are affected by this. Exceptions can be
made later.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16: assign the first available bug number]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 6cbd2171e8 upstream.
There is currently no way to force CPU bug bits like CPU feature bits. That
makes it impossible to set a bug bit once at boot and have it stick for all
upcoming CPUs.
Extend the force set/clear arrays to handle bug bits as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Link: https://lkml.kernel.org/r/20171204150606.992156574@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 01c9b17bf6 upstream.
Add some details about how PTI works, what some of the downsides
are, and how to debug it when things go wrong.
Also document the kernel parameter: 'pti/nopti'.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Moritz Lipp <moritz.lipp@iaik.tugraz.at>
Cc: Daniel Gruss <daniel.gruss@iaik.tugraz.at>
Cc: Michael Schwarz <michael.schwarz@iaik.tugraz.at>
Cc: Richard Fellner <richard.fellner@student.tugraz.at>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andi Lutomirsky <luto@kernel.org>
Link: https://lkml.kernel.org/r/20180105174436.1BC6FA2B@viggo.jf.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 0cb5b30698 upstream.
Guest GPR values are live in the hardware GPRs at VM-exit. Do not
leave any guest values in hardware GPRs after the guest GPR values are
saved to the vcpu_vmx structure.
This is a partial mitigation for CVE 2017-5715 and CVE 2017-5753.
Specifically, it defeats the Project Zero PoC for CVE 2017-5715.
Suggested-by: Eric Northup <digitaleric@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Eric Northup <digitaleric@google.com>
Reviewed-by: Benjamin Serebrin <serebrin@google.com>
Reviewed-by: Andrew Honig <ahonig@google.com>
[Paolo: Add AMD bits, Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 8dbc1864b7 upstream.
Commit 17278a91e0 ("MIPS: CPS: Fix r1 .set mt assembler warning")
added .set MIPS_ISA_LEVEL_RAW to silence warnings about .set mt on r1,
however this can result in a MOVE being encoded as a 64-bit DADDU
instruction on certain version of binutils (e.g. 2.22), and reserved
instruction exceptions at runtime on 32-bit hardware.
Reduce the sizes of the push/pop sections to include only instructions
that are part of the MT ASE or which won't convert to 64-bit
instructions after .set mips64r2/mips64r6.
Reported-by: Greg Ungerer <gerg@linux-m68k.org>
Fixes: 17278a91e0 ("MIPS: CPS: Fix r1 .set mt assembler warning")
Signed-off-by: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@linux-mips.org
Tested-by: Greg Ungerer <gerg@linux-m68k.org>
Patchwork: https://patchwork.linux-mips.org/patch/18578/
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 66b3bd2356 upstream.
The type of arg passed to dmatest_callback is struct dmatest_done.
It refers to test_done in struct dmatest_thread, not done_wait.
Fixes: 6f6a23a213 ("dmaengine: dmatest: move callback wait ...")
Signed-off-by: Yang Shunyong <shunyong.yang@hxt-semitech.com>
Acked-by: Adam Wallis <awallis@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 43cdd1b716 upstream.
There's no need to be printing a raw kernel pointer to the kernel log at
every boot. So just remove it, and change the whole message to use the
correct dev_info() call at the same time.
Reported-by: Wang Qize <wang_qize@venustech.com.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit a1dfb4c48c upstream.
The 32-bit compat v4l2 ioctl handling is implemented based on its 64-bit
equivalent. It converts 32-bit data structures into its 64-bit
equivalents and needs to provide the data to the 64-bit ioctl in user
space memory which is commonly allocated using
compat_alloc_user_space().
However, due to how that function is implemented, it can only be called
a single time for every syscall invocation.
Supposedly to avoid this limitation, the existing code uses a mix of
memory from the kernel stack and memory allocated through
compat_alloc_user_space().
Under normal circumstances, this would not work, because the 64-bit
ioctl expects all pointers to point to user space memory. As a
workaround, set_fs(KERNEL_DS) is called to temporarily disable this
extra safety check and allow kernel pointers. However, this might
introduce a security vulnerability: The result of the 32-bit to 64-bit
conversion is writeable by user space because the output buffer has been
allocated via compat_alloc_user_space(). A malicious user space process
could then manipulate pointers inside this output buffer, and due to the
previous set_fs(KERNEL_DS) call, functions like get_user() or put_user()
no longer prevent kernel memory access.
The new approach is to pre-calculate the total amount of user space
memory that is needed, allocate it using compat_alloc_user_space() and
then divide up the allocated memory to accommodate all data structures
that need to be converted.
An alternative approach would have been to retain the union type karg
that they allocated on the kernel stack in do_video_ioctl(), copy all
data from user space into karg and then back to user space. However, we
decided against this approach because it does not align with other
compat syscall implementations. Instead, we tried to replicate the
get_user/put_user pairs as found in other places in the kernel:
if (get_user(clipcount, &up->clipcount) ||
put_user(clipcount, &kp->clipcount)) return -EFAULT;
Notes from hans.verkuil@cisco.com:
This patch was taken from:
97b733953c
Clearly nobody could be bothered to upstream this patch or at minimum
tell us :-( We only heard about this a week ago.
This patch was rebased and cleaned up. Compared to the original I
also swapped the order of the convert_in_user arguments so that they
matched copy_in_user. It was hard to review otherwise. I also replaced
the ALLOC_USER_SPACE/ALLOC_AND_GET by a normal function.
Fixes: 6b5a9492ca ("v4l: introduce string control support.")
Signed-off-by: Daniel Mentz <danielmentz@google.com>
Co-developed-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
[bwh: Rebased on top of some earlier fixes]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit d83a8243aa upstream.
Some ioctls need to copy back the result even if the ioctl returned
an error. However, don't do this for the error code -ENOTTY.
It makes no sense in that cases.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 169f24ca68 upstream.
There is nothing wrong with using an unknown buffer type. So
stop spamming the kernel log whenever this happens. The kernel
will just return -EINVAL to signal this.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit a751be5b14 upstream.
put_v4l2_window32() didn't copy back the clip list to userspace.
Drivers can update the clip rectangles, so this should be done.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 025a26fa14 upstream.
Commit b2787845fb ("V4L/DVB (5289): Add support for video output
overlays.") added the field global_alpha to struct v4l2_window but did
not update the compat layer accordingly. This change adds global_alpha
to struct v4l2_window32 and copies the value for global_alpha back and
forth.
Signed-off-by: Daniel Mentz <danielmentz@google.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit b8c601e8af upstream.
ctrl_is_pointer just hardcoded two known string controls, but that
caused problems when using e.g. custom controls that use a pointer
for the payload.
Reimplement this function: it now finds the v4l2_ctrl (if the driver
uses the control framework) or it calls vidioc_query_ext_ctrl (if the
driver implements that directly).
In both cases it can now check if the control is a pointer control
or not.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
[bwh: Rebased on top of some earlier fixes]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 8ed5a59dcb upstream.
The struct v4l2_plane32 should set m.userptr as well. The same
happens in v4l2_buffer32 and v4l2-compliance tests for this.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 333b1e9f96 upstream.
Instead of doing sizeof(struct foo) use sizeof(*up). There even were
cases where 4 * sizeof(__u32) was used instead of sizeof(kp->reserved),
which is very dangerous when the size of the reserved array changes.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
[bwh: Rebased on top of some earlier fixes]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 486c521510 upstream.
These helper functions do not really help. Move the code to the
__get/put_v4l2_format32 functions.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
[bwh: Rebased on top of some earlier fixes]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit b7b957d429 upstream.
The indentation of this source is all over the place. Fix this.
This patch only changes whitespace.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
[bwh: Rebased on top of some earlier fixes]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 3ee6d04071 upstream.
The result of the VIDIOC_PREPARE_BUF ioctl was never copied back
to userspace since it was missing in the switch.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 3171cc2b4e upstream.
According to the doc, V4L2_BUF_FLAG_DONE is cleared after DQBUF:
V4L2_BUF_FLAG_DONE 0x00000004 ... After calling the VIDIOC_QBUF or
VIDIOC_DQBUF it is always cleared ...
Unfortunately, it seems that videobuf2 keeps it set after DQBUF. This
can be tested with vivid and dev_debug:
[257604.338082] video1: VIDIOC_DQBUF: 71:33:25.00260479 index=3,
type=vid-cap, flags=0x00002004, field=none, sequence=163,
memory=userptr, bytesused=460800, offset/userptr=0x344b000,
length=460800
This patch forces FLAG_DONE to 0 after calling DQBUF.
Reported-by: Dimitrios Katsaros <patcherwork@gmail.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 181a4a2d5a upstream.
If the ioctl returned -ENOTTY, then don't bother copying
back the result as there is no point.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
The prefix is ADV7604_, not ADV76XX.
Fixes: f31b62e14a ("adv7604: add hdmi driver strength adjustment")
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 037e0865c2 upstream.
The v4l2_input32 struct wasn't updated when this field was added.
It didn't cause a failure in the compat code, but it is better to
keep it in sync with v4l2_input to avoid confusion.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit baf43c6eac upstream.
In v4l2-compliance utility, test VIDIOC_CREATE_BUFS will check whether reserved
filed of v4l2_create_buffers filled with zero
Reserved field is filled with zero in v4l_create_bufs.
This patch copy reserved field of v4l2_create_buffer from kernel space to user
space
Signed-off-by: Tiffany Lin <tiffany.lin@mediatek.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 6ed9b28504 upstream.
Similar to an earlier patch, fixing reading user-space data for the
VIDIOC_CREATE_BUFS ioctl() in 32-bit compatibility mode, this patch fixes
writing back of the possibly modified struct to the user. However, unlike
the former bug, this one is much less harmful, because it only results in
the kernel failing to write the .type field back to the user, but in fact
this is likely unneeded, because the kernel will hardly want to change
that field. Therefore this bug is more of a theoretical nature.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 8ae632b117 upstream.
A lot of these warnings are caused by the fact that we don't generally use
__user in videodev2.h. Normally the video_usercopy function will copy anything
pointed to by pointers into kernel space, so having __user in the struct will only
cause lots of warnings in the drivers. But the flip side of that is that you
need to add __force casts here.
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:337:26: warning: incorrect type in argument 1 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:337:30: warning: incorrect type in argument 2 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:338:31: warning: incorrect type in argument 1 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:338:49: warning: incorrect type in argument 2 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:343:21: warning: incorrect type in argument 1 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:346:21: warning: incorrect type in argument 1 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:349:35: warning: incorrect type in argument 1 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:349:46: warning: incorrect type in argument 2 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:352:35: warning: incorrect type in argument 1 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:352:54: warning: incorrect type in argument 2 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:363:26: warning: incorrect type in argument 1 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:363:32: warning: incorrect type in argument 2 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:364:31: warning: incorrect type in argument 1 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:364:51: warning: incorrect type in argument 2 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:371:35: warning: incorrect type in argument 1 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:371:56: warning: incorrect type in argument 2 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:376:35: warning: incorrect type in argument 1 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:376:48: warning: incorrect type in argument 2 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:430:30: warning: incorrect type in assignment (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:433:48: warning: incorrect type in argument 1 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:433:56: warning: incorrect type in argument 2 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:501:24: warning: incorrect type in assignment (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:507:48: warning: incorrect type in argument 1 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:507:56: warning: incorrect type in argument 2 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:565:18: warning: incorrect type in assignment (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:670:22: warning: incorrect type in assignment (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:680:29: warning: incorrect type in assignment (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:692:55: warning: incorrect type in initializer (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:773:18: warning: incorrect type in assignment (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:786:30: warning: incorrect type in argument 1 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:786:44: warning: incorrect type in argument 2 (different address spaces)
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:674:37: warning: dereference of noderef expression
drivers/media/v4l2-core/v4l2-compat-ioctl32.c:718:37: warning: dereference of noderef expression
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 5d26b50813 upstream.
The dividend in do_div() is expected to be an unsigned 64-bit integer,
which leads to the following warning when building for 32-bit MIPS:
drivers/net/wireless/mac80211_hwsim.c: In function 'mac80211_hwsim_set_tsf':
drivers/net/wireless/mac80211_hwsim.c:664:98: warning: comparison of distinct pointer types lacks a cast [enabled by default]
data->bcn_delta = do_div(delta, bcn_int);
Since we care about the signedness of delta when adjusting tsf_offset
and bcm_delta, use the absolute value for the division and compare
the two timestamps to determine the sign.
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit fac25940c5 upstream.
If bcmgenet_init_dma() fails, it cleans up after itself. Rx and Tx
DMAs are off, and NAPI instances haven't been netif_napi_add()'ed.
Therefore, we need to skip calling bcmgenet_fini_dma() on the error
handling path. bcmgenet_resume() already does this correctly.
Signed-off-by: Petri Gynther <pgynther@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Commit 49e67dd176 "of: fdt: add missing allocation-failure check"
added a "return NULL" statement in __unflatten_device_tree(). When
applied to the 3.16-stable branch, this introduced a compiler warning
(not an error!) because the function returns void here.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit d5421ea43d upstream.
The hrtimer interrupt code contains a hang detection and mitigation
mechanism, which prevents that a long delayed hrtimer interrupt causes a
continous retriggering of interrupts which prevent the system from making
progress. If a hang is detected then the timer hardware is programmed with
a certain delay into the future and a flag is set in the hrtimer cpu base
which prevents newly enqueued timers from reprogramming the timer hardware
prior to the chosen delay. The subsequent hrtimer interrupt after the delay
clears the flag and resumes normal operation.
If such a hang happens in the last hrtimer interrupt before a CPU is
unplugged then the hang_detected flag is set and stays that way when the
CPU is plugged in again. At that point the timer hardware is not armed and
it cannot be armed because the hang_detected flag is still active, so
nothing clears that flag. As a consequence the CPU does not receive hrtimer
interrupts and no timers expire on that CPU which results in RCU stalls and
other malfunctions.
Clear the flag along with some other less critical members of the hrtimer
cpu base to ensure starting from a clean state when a CPU is plugged in.
Thanks to Paul, Sebastian and Anna-Maria for their help to get down to the
root cause of that hard to reproduce heisenbug. Once understood it's
trivial and certainly justifies a brown paperbag.
Fixes: 41d2e49493 ("hrtimer: Tune hrtimer_interrupt hang logic")
Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Sewior <bigeasy@linutronix.de>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1801261447590.2067@nanos
[bwh: Backported to 3.16:
- There's no next_timer field to reset
- Adjust filename, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit dd5684ecae upstream.
ccid2_hc_tx_rto_expire() timer callback always restarts the timer
again and can run indefinitely (unless it is stopped outside), and after
commit 120e9dabaf ("dccp: defer ccid_hc_tx_delete() at dismantle time"),
which moved ccid_hc_tx_delete() (also includes sk_stop_timer()) from
dccp_destroy_sock() to sk_destruct(), this started to happen quite often.
The timer prevents releasing the socket, as a result, sk_destruct() won't
be called.
Found with LTP/dccp_ipsec tests running on the bonding device,
which later couldn't be unloaded after the tests were completed:
unregister_netdevice: waiting for bond0 to become free. Usage count = 148
Fixes: 2a91aa3967 ("[DCCP] CCID2: Initial CCID2 (TCP-Like) implementation")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 7e702d17ed upstream.
Commit b94b737331 ("x86/microcode/intel: Extend BDW late-loading with a
revision check") reduced the impact of erratum BDF90 for Broadwell model
79.
The impact can be reduced further by checking the size of the last level
cache portion per core.
Tony: "The erratum says the problem only occurs on the large-cache SKUs.
So we only need to avoid the update if we are on a big cache SKU that is
also running old microcode."
For more details, see erratum BDF90 in document #334165 (Intel Xeon
Processor E7-8800/4800 v4 Product Family Specification Update) from
September 2017.
Fixes: b94b737331 ("x86/microcode/intel: Extend BDW late-loading with a revision check")
Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/1516321542-31161-1-git-send-email-zhang.jia@linux.alibaba.com
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 02612bb05e upstream.
In pppoe_sendmsg(), reserving dev->hard_header_len bytes of headroom
was probably fine before the introduction of ->needed_headroom in
commit f5184d267c ("net: Allow netdevices to specify needed head/tailroom").
But now, virtual devices typically advertise the size of their overhead
in dev->needed_headroom, so we must also take it into account in
skb_reserve().
Allocation size of skb is also updated to take dev->needed_tailroom
into account and replace the arbitrary 32 bytes with the real size of
a PPPoE header.
This issue was discovered by syzbot, who connected a pppoe socket to a
gre device which had dev->header_ops->create == ipgre_header and
dev->hard_header_len == 0. Therefore, PPPoE didn't reserve any
headroom, and dev_hard_header() crashed when ipgre_header() tried to
prepend its header to skb->data.
skbuff: skb_under_panic: text:000000001d390b3a len:31 put:24
head:00000000d8ed776f data:000000008150e823 tail:0x7 end:0xc0 dev:gre0
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:104!
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 3670 Comm: syzkaller801466 Not tainted
4.15.0-rc7-next-20180115+ #97
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:skb_panic+0x162/0x1f0 net/core/skbuff.c:100
RSP: 0018:ffff8801d9bd7840 EFLAGS: 00010282
RAX: 0000000000000083 RBX: ffff8801d4f083c0 RCX: 0000000000000000
RDX: 0000000000000083 RSI: 1ffff1003b37ae92 RDI: ffffed003b37aefc
RBP: ffff8801d9bd78a8 R08: 1ffff1003b37ae8a R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffffff86200de0
R13: ffffffff84a981ad R14: 0000000000000018 R15: ffff8801d2d34180
FS: 00000000019c4880(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000208bc000 CR3: 00000001d9111001 CR4: 00000000001606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
skb_under_panic net/core/skbuff.c:114 [inline]
skb_push+0xce/0xf0 net/core/skbuff.c:1714
ipgre_header+0x6d/0x4e0 net/ipv4/ip_gre.c:879
dev_hard_header include/linux/netdevice.h:2723 [inline]
pppoe_sendmsg+0x58e/0x8b0 drivers/net/ppp/pppoe.c:890
sock_sendmsg_nosec net/socket.c:630 [inline]
sock_sendmsg+0xca/0x110 net/socket.c:640
sock_write_iter+0x31a/0x5d0 net/socket.c:909
call_write_iter include/linux/fs.h:1775 [inline]
do_iter_readv_writev+0x525/0x7f0 fs/read_write.c:653
do_iter_write+0x154/0x540 fs/read_write.c:932
vfs_writev+0x18a/0x340 fs/read_write.c:977
do_writev+0xfc/0x2a0 fs/read_write.c:1012
SYSC_writev fs/read_write.c:1085 [inline]
SyS_writev+0x27/0x30 fs/read_write.c:1082
entry_SYSCALL_64_fastpath+0x29/0xa0
Admittedly PPPoE shouldn't be allowed to run on non Ethernet-like
interfaces, but reserving space for ->needed_headroom is a more
fundamental issue that needs to be addressed first.
Same problem exists for __pppoe_xmit(), which also needs to take
dev->needed_headroom into account in skb_cow_head().
Fixes: f5184d267c ("net: Allow netdevices to specify needed head/tailroom")
Reported-by: syzbot+ed0838d0fa4c4f2b528e20286e6dc63effc7c14d@syzkaller.appspotmail.com
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
