- 03 Apr, 2018 31 commits
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Hugh Dickins authored
BugLink: http://bugs.launchpad.net/bugs/1755509 Vince reported perf_fuzzer quickly locks up on 4.15-rc7 with PTI; Robert reported Bad RIP with KPTI and Intel BTS also on 4.15-rc7: honggfuzz -f /tmp/somedirectorywithatleastonefile \ --linux_perf_bts_edge -s -- /bin/true (honggfuzz from https://github.com/google/honggfuzz) crashed with BUG: unable to handle kernel paging request at ffff9d3215100000 (then narrowed it down to perf record --per-thread -e intel_bts//u -- /bin/ls). The intel_bts driver does not use the 'normal' BTS buffer which is exposed through kaiser_add_mapping(), but instead uses the memory allocated for the perf AUX buffer. This obviously comes apart when using PTI, because then the kernel mapping, which includes that AUX buffer memory, disappears while switched to user page tables. Easily fixed in old-Kaiser backports, by applying kaiser_add_mapping() to those pages; perhaps not so easy for upstream, where 4.15-rc8 commit 99a9dc98 ("x86,perf: Disable intel_bts when PTI") disables for now. Slightly reorganized surrounding code in bts_buffer_setup_aux(), so it can better match bts_buffer_free_aux(): free_aux with an #ifdef to avoid the loop when PTI is off, but setup_aux needs to loop anyway (and kaiser_add_mapping() is cheap when PTI config is off or "pti=off"). Reported-by:
Vince Weaver <vincent.weaver@maine.edu> Reported-by:
Robert Święcki <robert@swiecki.net> Analyzed-by:
Peter Zijlstra <peterz@infradead.org> Analyzed-by:
Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Vince Weaver <vince@deater.net> Cc: stable@vger.kernel.org Cc: Jiri Kosina <jkosina@suze.cz> Signed-off-by:
Hugh Dickins <hughd@google.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
Juerg Haefliger <juergh@canonical.com> Signed-off-by:
Stefan Bader <stefan.bader@canonical.com>
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Dave Hansen authored
BugLink: http://bugs.launchpad.net/bugs/1755509 commit 445b69e3 upstream. The inital fix for trusted boot and PTI potentially misses the pgd clearing if pud_alloc() sets a PGD. It probably works in *practice* because for two adjacent calls to map_tboot_page() that share a PGD entry, the first will clear NX, *then* allocate and set the PGD (without NX clear). The second call will *not* allocate but will clear the NX bit. Defer the NX clearing to a point after it is known that all top-level allocations have occurred. Add a comment to clarify why. [ tglx: Massaged changelog ] [hughd notes: I have not tested tboot, but this looks to me as necessary and as safe in old-Kaiser backports as it is upstream; I'm not submitting the commit-to-be-fixed 262b6b30, since it was undone by 445b69e3, and makes conflict trouble because of 5-level's p4d versus 4-level's pgd.] Fixes: 262b6b30 ("x86/tboot: Unbreak tboot with PTI enabled") Signed-off-by:
Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Reviewed-by:
Andrea Arcangeli <aarcange@redhat.com> Cc: Jon Masters <jcm@redhat.com> Cc: "Tim Chen" <tim.c.chen@linux.intel.com> Cc: gnomes@lxorguk.ukuu.org.uk Cc: peterz@infradead.org Cc: ning.sun@intel.com Cc: tboot-devel@lists.sourceforge.net Cc: andi@firstfloor.org Cc: luto@kernel.org Cc: law@redhat.com Cc: pbonzini@redhat.com Cc: torvalds@linux-foundation.org Cc: gregkh@linux-foundation.org Cc: dwmw@amazon.co.uk Cc: nickc@redhat.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180110224939.2695CD47@viggo.jf.intel.comSigned-off-by:
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Daniel Borkmann authored
BugLink: http://bugs.launchpad.net/bugs/1755509 [ upstream commit f37a8cb8 ] Alexei found that verifier does not reject stores into context via BPF_ST instead of BPF_STX. And while looking at it, we also should not allow XADD variant of BPF_STX. The context rewriter is only assuming either BPF_LDX_MEM- or BPF_STX_MEM-type operations, thus reject anything other than that so that assumptions in the rewriter properly hold. Add test cases as well for BPF selftests. Fixes: d691f9e8 ("bpf: allow programs to write to certain skb fields") Reported-by:
Alexei Starovoitov <ast@kernel.org> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Signed-off-by:
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Alexei Starovoitov authored
BugLink: http://bugs.launchpad.net/bugs/1755509 [ upstream commit 68fda450 ] due to some JITs doing if (src_reg == 0) check in 64-bit mode for div/mod operations mask upper 32-bits of src register before doing the check Fixes: 62258278 ("net: filter: x86: internal BPF JIT") Fixes: 7a12b503 ("sparc64: Add eBPF JIT.") Reported-by: syzbot+48340bb518e88849e2e3@syzkaller.appspotmail.com Signed-off-by:
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Eric Dumazet authored
BugLink: http://bugs.launchpad.net/bugs/1755509 [ upstream commit c366287e ] Divides by zero are not nice, lets avoid them if possible. Also do_div() seems not needed when dealing with 32bit operands, but this seems a minor detail. Fixes: bd4cf0ed ("net: filter: rework/optimize internal BPF interpreter's instruction set") Signed-off-by:
Eric Dumazet <edumazet@google.com> Reported-by:
syzbot <syzkaller@googlegroups.com> Signed-off-by:
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Daniel Borkmann authored
BugLink: http://bugs.launchpad.net/bugs/1755509 [ upstream commit be95a845 ] In addition to commit b2157399 ("bpf: prevent out-of-bounds speculation") also change the layout of struct bpf_map such that false sharing of fast-path members like max_entries is avoided when the maps reference counter is altered. Therefore enforce them to be placed into separate cachelines. pahole dump after change: struct bpf_map { const struct bpf_map_ops * ops; /* 0 8 */ struct bpf_map * inner_map_meta; /* 8 8 */ void * security; /* 16 8 */ enum bpf_map_type map_type; /* 24 4 */ u32 key_size; /* 28 4 */ u32 value_size; /* 32 4 */ u32 max_entries; /* 36 4 */ u32 map_flags; /* 40 4 */ u32 pages; /* 44 4 */ u32 id; /* 48 4 */ int numa_node; /* 52 4 */ bool unpriv_array; /* 56 1 */ /* XXX 7 bytes hole, try to pack */ /* --- cacheline 1 boundary (64 bytes) --- */ struct user_struct * user; /* 64 8 */ atomic_t refcnt; /* 72 4 */ atomic_t usercnt; /* 76 4 */ struct work_struct work; /* 80 32 */ char name[16]; /* 112 16 */ /* --- cacheline 2 boundary (128 bytes) --- */ /* size: 128, cachelines: 2, members: 17 */ /* sum members: 121, holes: 1, sum holes: 7 */ }; Now all entries in the first cacheline are read only throughout the life time of the map, set up once during map creation. Overall struct size and number of cachelines doesn't change from the reordering. struct bpf_map is usually first member and embedded in map structs in specific map implementations, so also avoid those members to sit at the end where it could potentially share the cacheline with first map values e.g. in the array since remote CPUs could trigger map updates just as well for those (easily dirtying members like max_entries intentionally as well) while having subsequent values in cache. Quoting from Google's Project Zero blog [1]: Additionally, at least on the Intel machine on which this was tested, bouncing modified cache lines between cores is slow, apparently because the MESI protocol is used for cache coherence [8]. Changing the reference counter of an eBPF array on one physical CPU core causes the cache line containing the reference counter to be bounced over to that CPU core, making reads of the reference counter on all other CPU cores slow until the changed reference counter has been written back to memory. Because the length and the reference counter of an eBPF array are stored in the same cache line, this also means that changing the reference counter on one physical CPU core causes reads of the eBPF array's length to be slow on other physical CPU cores (intentional false sharing). While this doesn't 'control' the out-of-bounds speculation through masking the index as in commit b2157399, triggering a manipulation of the map's reference counter is really trivial, so lets not allow to easily affect max_entries from it. Splitting to separate cachelines also generally makes sense from a performance perspective anyway in that fast-path won't have a cache miss if the map gets pinned, reused in other progs, etc out of control path, thus also avoids unintentional false sharing. [1] https://googleprojectzero.blogspot.ch/2018/01/reading-privileged-memory-with-side.htmlSigned-off-by:
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Daniel Borkmann authored
BugLink: http://bugs.launchpad.net/bugs/1755509 [ upstream commit 7891a87e ] The following snippet was throwing an 'unknown opcode cc' warning in BPF interpreter: 0: (18) r0 = 0x0 2: (7b) *(u64 *)(r10 -16) = r0 3: (cc) (u32) r0 s>>= (u32) r0 4: (95) exit Although a number of JITs do support BPF_ALU | BPF_ARSH | BPF_{K,X} generation, not all of them do and interpreter does neither. We can leave existing ones and implement it later in bpf-next for the remaining ones, but reject this properly in verifier for the time being. Fixes: 17a52670 ("bpf: verifier (add verifier core)") Reported-by: syzbot+93c4904c5c70348a6890@syzkaller.appspotmail.com Signed-off-by:
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Alexei Starovoitov authored
BugLink: http://bugs.launchpad.net/bugs/1755509 [ upstream commit 290af866 ] The BPF interpreter has been used as part of the spectre 2 attack CVE-2017-5715. A quote from goolge project zero blog: "At this point, it would normally be necessary to locate gadgets in the host kernel code that can be used to actually leak data by reading from an attacker-controlled location, shifting and masking the result appropriately and then using the result of that as offset to an attacker-controlled address for a load. But piecing gadgets together and figuring out which ones work in a speculation context seems annoying. So instead, we decided to use the eBPF interpreter, which is built into the host kernel - while there is no legitimate way to invoke it from inside a VM, the presence of the code in the host kernel's text section is sufficient to make it usable for the attack, just like with ordinary ROP gadgets." To make attacker job harder introduce BPF_JIT_ALWAYS_ON config option that removes interpreter from the kernel in favor of JIT-only mode. So far eBPF JIT is supported by: x64, arm64, arm32, sparc64, s390, powerpc64, mips64 The start of JITed program is randomized and code page is marked as read-only. In addition "constant blinding" can be turned on with net.core.bpf_jit_harden v2->v3: - move __bpf_prog_ret0 under ifdef (Daniel) v1->v2: - fix init order, test_bpf and cBPF (Daniel's feedback) - fix offloaded bpf (Jakub's feedback) - add 'return 0' dummy in case something can invoke prog->bpf_func - retarget bpf tree. For bpf-next the patch would need one extra hunk. It will be sent when the trees are merged back to net-next Considered doing: int bpf_jit_enable __read_mostly = BPF_EBPF_JIT_DEFAULT; but it seems better to land the patch as-is and in bpf-next remove bpf_jit_enable global variable from all JITs, consolidate in one place and remove this jit_init() function. Signed-off-by:
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Juerg Haefliger authored
BugLink: http://bugs.launchpad.net/bugs/1755509 New config option pulled in with the update to stable release 4.4.115. Signed-off-by:
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Alexei Starovoitov authored
BugLink: http://bugs.launchpad.net/bugs/1755509 [ upstream commit 90caccdd ] - bpf prog_array just like all other types of bpf array accepts 32-bit index. Clarify that in the comment. - fix x64 JIT of bpf_tail_call which was incorrectly loading 8 instead of 4 bytes - tighten corresponding check in the interpreter to stay consistent The JIT bug can be triggered after introduction of BPF_F_NUMA_NODE flag in commit 96eabe7a in 4.14. Before that the map_flags would stay zero and though JIT code is wrong it will check bounds correctly. Hence two fixes tags. All other JITs don't have this problem. Signed-off-by:
Martin KaFai Lau <kafai@fb.com> Reviewed-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
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Eric Dumazet authored
BugLink: http://bugs.launchpad.net/bugs/1755509 [ upstream commit 84ccac6e ] Saves 4 bytes replacing following instructions : lea rax, [rsi + rdx * 8 + offsetof(...)] mov rax, qword ptr [rax] cmp rax, 0 by : mov rax, [rsi + rdx * 8 + offsetof(...)] test rax, rax Signed-off-by:
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Seth Forshee authored
The recent update to handle multiple bugs/cves has an error in the detection of packaging changes, causing them to be denoted as upstream changes in the changelog. Change this logic to check the subject field instead of the non-existent title field. Ignore: yes Signed-off-by:
Seth Forshee <seth.forshee@canonical.com> Acked-by:
Kleber Sacilotto de Souza <kleber.souza@canonical.com> Signed-off-by:
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Andy Whitcroft authored
BugLink: http://bugs.launchpad.net/bugs/1758856Signed-off-by:
Andy Whitcroft <apw@canonical.com> Acked-by:
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Andy Whitcroft authored
BugLink: http://bugs.launchpad.net/bugs/1758856Signed-off-by:
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Andy Whitcroft authored
BugLink: http://bugs.launchpad.net/bugs/1758856Signed-off-by:
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Peter Zijlstra authored
BugLink: http://bugs.launchpad.net/bugs/1758856 The objtool retpoline validation found this indirect jump. Seeing how it's on CPU bringup before we run userspace it should be safe, annotate it. Signed-off-by:
David Woodhouse <dwmw@amazon.co.uk> Acked-by:
Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by:
Ingo Molnar <mingo@kernel.org> (backported from commit bd89004f) Signed-off-by:
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Peter Zijlstra authored
BugLink: http://bugs.launchpad.net/bugs/1758856 Replace indirect call with CALL_NOSPEC. Signed-off-by:
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Peter Zijlstra authored
BugLink: http://bugs.launchpad.net/bugs/1758856 Replace the indirect calls with CALL_NOSPEC. Signed-off-by:
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Andy Whitcroft authored
BugLink: http://bugs.launchpad.net/bugs/1758856Signed-off-by:
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Andy Whitcroft authored
BugLink: http://bugs.launchpad.net/bugs/1758856Signed-off-by:
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Andy Whitcroft authored
BugLink: http://bugs.launchpad.net/bugs/1758856 These are always safe because there is no way rip can be an unknown. Signed-off-by:
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Andy Whitcroft authored
BugLink: http://bugs.launchpad.net/bugs/1758856Signed-off-by:
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Andy Whitcroft authored
BugLink: http://bugs.launchpad.net/bugs/1758856Signed-off-by:
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Andy Whitcroft authored
BugLink: http://bugs.launchpad.net/bugs/1758856 Use the upstream retpoline safe hinting support to clear out known safe retpoline sequences from those detected. At the same time switch to extracting the indirect sequences and associated hints to .o generation time. This allows it to be run on the cache hot data and to be run in parallel on the builders. Signed-off-by:
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Andy Lutomirski authored
BugLink: http://bugs.launchpad.net/bugs/1758856 alternative.h pulls in ptrace.h, which means that alternatives can't be used in anything referenced from ptrace.h, which is a mess. Break the dependency by pulling text patching helpers into their own header. Signed-off-by:
Andy Lutomirski <luto@kernel.org> 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: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/99b93b13f2c9eb671f5c98bba4c2cbdc061293a2.1461698311.git.luto@kernel.orgSigned-off-by:
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Peter Zijlstra authored
BugLink: http://bugs.launchpad.net/bugs/1758856 Paravirt emits indirect calls which get flagged by objtool retpoline checks, annotate it away because all these indirect calls will be patched out before we start userspace. This patching happens through alternative_instructions() -> apply_paravirt() -> pv_init_ops.patch() which will eventually end up in paravirt_patch_default(). This function _will_ write direct alternatives. Signed-off-by:
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Andy Whitcroft authored
BugLink: http://bugs.launchpad.net/bugs/1758856 In 9e0e3c51 ("x86/speculation, objtool: Annotate indirect calls/jumps for objtool") we added annotations for CALL_NOSPEC/JMP_NOSPEC on x86 64bit. We did not annotate the 32bit path. Annotate it similarly. [apw@canonical.com: backported to xenial.] Signed-off-by:
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Peter Zijlstra authored
BugLink: http://bugs.launchpad.net/bugs/1758856 Annotate the indirect calls/jumps in the CALL_NOSPEC/JUMP_NOSPEC alternatives. Signed-off-by:
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Steve Beattie authored
BugLink: http://bugs.launchpad.net/bugs/1758856 Catch indirect jmps and calls of the form 'jmp *0xNNNN(%reg)'. Signed-off-by:
Steve Beattie <steve.beattie@canonical.com> Acked-by:
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Andy Whitcroft authored
BugLink: http://bugs.launchpad.net/bugs/1752655Signed-off-by:
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Juerg Haefliger authored
Ignore: yes Signed-off-by:
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- 31 Mar, 2018 4 commits
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Khalid Elmously authored
Signed-off-by:Khalid Elmously <khalid.elmously@canonical.com>
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Khalid Elmously authored
Retpoline files for i386 are empty for the previous ABIs. It has been fixed by commit "UBUNTU: [Packaging] retpoline-extract -- instantiate retpoline files for i386". So ignore the check from the previous ABI files. Ignore: yes Signed-off-by: -
Kai-Heng Feng authored
BugLink: http://bugs.launchpad.net/bugs/1759821 This reverts commit fd865802. This commit causes a regression on some QCA ROME chips. The USB device reset happens in btusb_open(), hence firmware loading gets interrupted. Furthermore, this commit stops working after commit ("a0085f25 Bluetooth: btusb: driver to enable the usb-wakeup feature"). Reset-resume quirk only gets enabled in btusb_suspend() when it's not a wakeup source. If we really want to reset the USB device, we need to do it before btusb_open(). Let's handle it in drivers/usb/core/quirks.c. Cc: stable@vger.kernel.org Cc: Leif Liddy <leif.linux@gmail.com> Cc: Matthias Kaehlcke <mka@chromium.org> Cc: Brian Norris <briannorris@chromium.org> Cc: Daniel Drake <drake@endlessm.com> Signed-off-by:
Kai-Heng Feng <kai.heng.feng@canonical.com> Reviewed-by:
Brian Norris <briannorris@chromium.org> Tested-by:
Marcel Holtmann <marcel@holtmann.org> (cherry picked from commit 7d06d589) Signed-off-by:
Joseph Salisbury <joseph.salisbury@canonical.com> Acked-by:
Brad Figg <brad.figg@canonical.com> Acked-by:
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Khalid Elmously authored
Ignore: yes Signed-off-by:
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- 28 Mar, 2018 5 commits
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Khalid Elmously authored
Signed-off-by: -
Khalid Elmously authored
Retpoline files for i386 are empty for the previous ABIs. It has been fixed by commit "UBUNTU: [Packaging] retpoline-extract -- instantiate retpoline files for i386". So ignore the check from the previous ABI files. Ignore: yes Signed-off-by: -
Borislav Petkov authored
BugLink: http://bugs.launchpad.net/bugs/1758869 commit a15a7535 upstream with minor adjustments. Doing so is completely void of sense for multiple reasons so prevent it. Set dis_ucode_ldr to true and thus disable the microcode loader by default to address xen pv guests which execute the AP path but not the BSP path. By having it turned off by default, the APs won't run into the loader either. Also, check CPUID(1).ECX[31] which hypervisors set. Well almost, not the xen pv one. That one gets the aforementioned "fix". Also, improve the detection method by caching the final decision whether to continue loading in dis_ucode_ldr and do it once on the BSP. The APs then simply test that value. Signed-off-by:
Borislav Petkov <bp@suse.de> Tested-by:
Juergen Gross <jgross@suse.com> Tested-by:
Boris Ostrovsky <boris.ostrovsky@oracle.com> Acked-by:
Rolf Neugebauer <rolf.neugebauer@docker.com> (back-ported from commit a15a7535) Reference: https://lkml.org/lkml/2018/2/8/455Acked-by:
Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by:
Kamal Mostafa <kamal@canonical.com>
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Wei Yongjun authored
CVE-2018-8043 platform_get_resource() may fail and return NULL, so we should better check it's return value to avoid a NULL pointer dereference a bit later in the code. This is detected by Coccinelle semantic patch. @@ expression pdev, res, n, t, e, e1, e2; @@ res = platform_get_resource(pdev, t, n); + if (!res) + return -EINVAL; ... when != res == NULL e = devm_ioremap(e1, res->start, e2); Signed-off-by:
Wei Yongjun <weiyongjun1@huawei.com> Signed-off-by:
Po-Hsu Lin <po-hsu.lin@canonical.com> Acked-by:
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Stefan Bader authored
Ignore: yes Signed-off-by:
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