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Filename Latest commit message Latest commit date
Kan Liang da326ba3b8 perf/x86/intel: Fix a crash caused by zero PEBS status
commit d88d05a9e0b6d9356e97129d4ff9942d765f46ea upstream.

A repeatable crash can be triggered by the perf_fuzzer on some Haswell
system.
https://lore.kernel.org/lkml/7170d3b-c17f-1ded-52aa-cc6d9ae999f4@maine.edu/

For some old CPUs (HSW and earlier), the PEBS status in a PEBS record
may be mistakenly set to 0. To minimize the impact of the defect, the
commit was introduced to try to avoid dropping the PEBS record for some
cases. It adds a check in the intel_pmu_drain_pebs_nhm(), and updates
the local pebs_status accordingly. However, it doesn't correct the PEBS
status in the PEBS record, which may trigger the crash, especially for
the large PEBS.

It's possible that all the PEBS records in a large PEBS have the PEBS
status 0. If so, the first get_next_pebs_record_by_bit() in the
__intel_pmu_pebs_event() returns NULL. The at = NULL. Since it's a large
PEBS, the 'count' parameter must > 1. The second
get_next_pebs_record_by_bit() will crash.

Besides the local pebs_status, correct the PEBS status in the PEBS
record as well.

Fixes: 01330d7288 ("perf/x86: Allow zero PEBS status with only single active event")
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1615555298-140216-1-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-24 11:26:43 +01:00
arch perf/x86/intel: Fix a crash caused by zero PEBS status 2021-03-24 11:26:43 +01:00
block blk-settings: align max_sectors on "logical_block_size" boundary 2021-03-04 10:26:40 +01:00
certs certs: Fix blacklist flag type confusion 2021-03-04 10:26:29 +01:00
crypto crypto: x86 - Regularize glue function prototypes 2021-03-20 10:39:47 +01:00
Documentation KVM: arm64: Reject VM creation when the default IPA size is unsupported 2021-03-17 17:03:57 +01:00
drivers PCI: rpadlpar: Fix potential drc_name corruption in store functions 2021-03-24 11:26:43 +01:00
fs nfsd: Don't keep looking up unhashed files in the nfsd file cache 2021-03-24 11:26:38 +01:00
include USB: replace hardcode maximum usb string length by definition 2021-03-24 11:26:41 +01:00
init fgraph: Initialize tracing_graph_pause at task creation 2021-02-10 09:25:29 +01:00
ipc
kernel bpf: Add sanity check for upper ptr_limit 2021-03-20 10:39:46 +01:00
lib PCI: Fix pci_register_io_range() memory leak 2021-03-17 17:03:44 +01:00
LICENSES
mm Revert "mm, slub: consider rest of partial list if acquire_slab() fails" 2021-03-17 17:03:34 +01:00
net net/qrtr: fix __netdev_alloc_skb call 2021-03-24 11:26:39 +01:00
samples samples, bpf: Add missing munmap in xdpsock 2021-03-17 17:03:33 +01:00
scripts ftrace: Have recordmcount use w8 to read relp->r_info in arm64_is_fake_mcount 2021-03-09 11:09:39 +01:00
security Revert 95ebabde382c ("capabilities: Don't allow writing ambiguous v3 file capabilities") 2021-03-17 17:03:47 +01:00
sound ASoC: simple-card-utils: Do not handle device clock 2021-03-24 11:26:37 +01:00
tools bpf, selftests: Fix up some test_verifier cases for unprivileged 2021-03-20 10:39:46 +01:00
usr
virt KVM: arm64: Ensure I-cache isolation between vcpus of a same VM 2021-03-17 17:03:57 +01:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS
Makefile kbuild: Fix <linux/version.h> for empty SUBLEVEL or PATCHLEVEL again 2021-03-24 11:26:39 +01:00
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Linux kernel
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There are several guides for kernel developers and users. These guides can
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There are various text files in the Documentation/ subdirectory,
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Please read the Documentation/process/changes.rst file, as it contains the
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