- 11 11月, 2017 1 次提交
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由 Josef Bacik 提交于
Error injection is sloppy and very ad-hoc. BPF could fill this niche perfectly with it's kprobe functionality. We could make sure errors are only triggered in specific call chains that we care about with very specific situations. Accomplish this with the bpf_override_funciton helper. This will modify the probe'd callers return value to the specified value and set the PC to an override function that simply returns, bypassing the originally probed function. This gives us a nice clean way to implement systematic error injection for all of our code paths. Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NJosef Bacik <jbacik@fb.com> Acked-by: NDaniel Borkmann <daniel@iogearbox.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 05 11月, 2017 7 次提交
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由 Roman Gushchin 提交于
Cgroup v2 lacks the device controller, provided by cgroup v1. This patch adds a new eBPF program type, which in combination of previously added ability to attach multiple eBPF programs to a cgroup, will provide a similar functionality, but with some additional flexibility. This patch introduces a BPF_PROG_TYPE_CGROUP_DEVICE program type. A program takes major and minor device numbers, device type (block/character) and access type (mknod/read/write) as parameters and returns an integer which defines if the operation should be allowed or terminated with -EPERM. Signed-off-by: NRoman Gushchin <guro@fb.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NTejun Heo <tj@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Jakub Kicinski 提交于
Thanks to the ability to load a program for a specific device, running verifier twice is no longer needed. Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Jakub Kicinski 提交于
If TC program is loaded with skip_sw flag, we should allow the device-specific programs to be accepted. Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: NSimon Horman <simon.horman@netronome.com> Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Jakub Kicinski 提交于
Pass the netdev pointer to bpf_prog_get_type(). This way BPF code can decide whether the device matches what the code was loaded/translated for. Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: NSimon Horman <simon.horman@netronome.com> Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Jakub Kicinski 提交于
Extend struct bpf_prog_info to contain information about program being bound to a device. Since the netdev may get destroyed while program still exists we need a flag to indicate the program is loaded for a device, even if the device is gone. Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: NSimon Horman <simon.horman@netronome.com> Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Jakub Kicinski 提交于
The fact that we don't know which device the program is going to be used on is quite limiting in current eBPF infrastructure. We have to reverse or limit the changes which kernel makes to the loaded bytecode if we want it to be offloaded to a networking device. We also have to invent new APIs for debugging and troubleshooting support. Make it possible to load programs for a specific netdev. This helps us to bring the debug information closer to the core eBPF infrastructure (e.g. we will be able to reuse the verifer log in device JIT). It allows device JITs to perform translation on the original bytecode. __bpf_prog_get() when called to get a reference for an attachment point will now refuse to give it if program has a device assigned. Following patches will add a version of that function which passes the expected netdev in. @type argument in __bpf_prog_get() is renamed to attach_type to make it clearer that it's only set on attachment. All calls to ndo_bpf are protected by rtnl, only verifier callbacks are not. We need a wait queue to make sure netdev doesn't get destroyed while verifier is still running and calling its driver. Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com> Reviewed-by: NSimon Horman <simon.horman@netronome.com> Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Chris Redpath 提交于
After commit 674e7541 (sched: cpufreq: Allow remote cpufreq callbacks) we stopped to always read the utilization for the CPU we are running the governor on, and instead we read it for the CPU which we've been told has updated utilization. This is stored in sugov_cpu->cpu. The value is set in sugov_register() but we clear it in sugov_start() which leads to always looking at the utilization of CPU0 instead of the correct one. Fix this by consolidating the initialization code into sugov_start(). Fixes: 674e7541 (sched: cpufreq: Allow remote cpufreq callbacks) Signed-off-by: NChris Redpath <chris.redpath@arm.com> Reviewed-by: NPatrick Bellasi <patrick.bellasi@arm.com> Reviewed-by: NBrendan Jackman <brendan.jackman@arm.com> Acked-by: NViresh Kumar <viresh.kumar@linaro.org> Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
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- 03 11月, 2017 3 次提交
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由 Craig Gallek 提交于
do_check() can fail early without allocating env->cur_state under memory pressure. Syzkaller found the stack below on the linux-next tree because of this. kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 1 PID: 27062 Comm: syz-executor5 Not tainted 4.14.0-rc7+ #106 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801c2c74700 task.stack: ffff8801c3e28000 RIP: 0010:free_verifier_state kernel/bpf/verifier.c:347 [inline] RIP: 0010:bpf_check+0xcf4/0x19c0 kernel/bpf/verifier.c:4533 RSP: 0018:ffff8801c3e2f5c8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 00000000fffffff4 RCX: 0000000000000000 RDX: 0000000000000070 RSI: ffffffff817d5aa9 RDI: 0000000000000380 RBP: ffff8801c3e2f668 R08: 0000000000000000 R09: 1ffff100387c5d9f R10: 00000000218c4e80 R11: ffffffff85b34380 R12: ffff8801c4dc6a28 R13: 0000000000000000 R14: ffff8801c4dc6a00 R15: ffff8801c4dc6a20 FS: 00007f311079b700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004d4a24 CR3: 00000001cbcd0000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bpf_prog_load+0xcbb/0x18e0 kernel/bpf/syscall.c:1166 SYSC_bpf kernel/bpf/syscall.c:1690 [inline] SyS_bpf+0xae9/0x4620 kernel/bpf/syscall.c:1652 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x452869 RSP: 002b:00007f311079abe8 EFLAGS: 00000212 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452869 RDX: 0000000000000030 RSI: 0000000020168000 RDI: 0000000000000005 RBP: 00007f311079aa20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000004b7550 R13: 00007f311079ab58 R14: 00000000004b7560 R15: 0000000000000000 Code: df 48 c1 ea 03 80 3c 02 00 0f 85 e6 0b 00 00 4d 8b 6e 20 48 b8 00 00 00 00 00 fc ff df 49 8d bd 80 03 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 b6 0b 00 00 49 8b bd 80 03 00 00 e8 d6 0c 26 RIP: free_verifier_state kernel/bpf/verifier.c:347 [inline] RSP: ffff8801c3e2f5c8 RIP: bpf_check+0xcf4/0x19c0 kernel/bpf/verifier.c:4533 RSP: ffff8801c3e2f5c8 ---[ end trace c8d37f339dc64004 ]--- Fixes: 638f5b90 ("bpf: reduce verifier memory consumption") Fixes: 1969db47 ("bpf: fix verifier memory leaks") Signed-off-by: NCraig Gallek <kraig@google.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NDaniel Borkmann <daniel@iogearbox.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Arnd Bergmann 提交于
The bpf_verifer_ops array is generated dynamically and may be empty depending on configuration, which then causes an out of bounds access: kernel/bpf/verifier.c: In function 'bpf_check': kernel/bpf/verifier.c:4320:29: error: array subscript is above array bounds [-Werror=array-bounds] This adds a check to the start of the function as a workaround. I would assume that the function is never called in that configuration, so the warning is probably harmless. Fixes: 00176a34 ("bpf: remove the verifier ops from program structure") Signed-off-by: NArnd Bergmann <arnd@arndb.de> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NDaniel Borkmann <daniel@iogearbox.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Arnd Bergmann 提交于
I ran into this link error with the latest net-next plus linux-next trees when networking is disabled: kernel/bpf/verifier.o:(.rodata+0x2958): undefined reference to `tc_cls_act_analyzer_ops' kernel/bpf/verifier.o:(.rodata+0x2970): undefined reference to `xdp_analyzer_ops' It seems that the code was written to deal with varying contents of the arrray, but the actual #ifdef was missing. Both tc_cls_act_analyzer_ops and xdp_analyzer_ops are defined in the core networking code, so adding a check for CONFIG_NET seems appropriate here, and I've verified this with many randconfig builds Fixes: 4f9218aa ("bpf: move knowledge about post-translation offsets out of verifier") Signed-off-by: NArnd Bergmann <arnd@arndb.de> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NDaniel Borkmann <daniel@iogearbox.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 02 11月, 2017 8 次提交
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由 Jiri Slaby 提交于
In commit 30d6e0a4 ("futex: Remove duplicated code and fix undefined behaviour"), I let FUTEX_WAKE_OP to fail on invalid op. Namely when op should be considered as shift and the shift is out of range (< 0 or > 31). But strace's test suite does this madness: futex(0x7fabd78bcffc, 0x5, 0xfacefeed, 0xb, 0x7fabd78bcffc, 0xa0caffee); futex(0x7fabd78bcffc, 0x5, 0xfacefeed, 0xb, 0x7fabd78bcffc, 0xbadfaced); futex(0x7fabd78bcffc, 0x5, 0xfacefeed, 0xb, 0x7fabd78bcffc, 0xffffffff); When I pick the first 0xa0caffee, it decodes as: 0x80000000 & 0xa0caffee: oparg is shift 0x70000000 & 0xa0caffee: op is FUTEX_OP_OR 0x0f000000 & 0xa0caffee: cmp is FUTEX_OP_CMP_EQ 0x00fff000 & 0xa0caffee: oparg is sign-extended 0xcaf = -849 0x00000fff & 0xa0caffee: cmparg is sign-extended 0xfee = -18 That means the op tries to do this: (futex |= (1 << (-849))) == -18 which is completely bogus. The new check of op in the code is: if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28)) { if (oparg < 0 || oparg > 31) return -EINVAL; oparg = 1 << oparg; } which results obviously in the "Invalid argument" errno: FAIL: futex =========== futex(0x7fabd78bcffc, 0x5, 0xfacefeed, 0xb, 0x7fabd78bcffc, 0xa0caffee) = -1: Invalid argument futex.test: failed test: ../futex failed with code 1 So let us soften the failure to print only a (ratelimited) message, crop the value and continue as if it were right. When userspace keeps up, we can switch this to return -EINVAL again. [v2] Do not return 0 immediatelly, proceed with the cropped value. Fixes: 30d6e0a4 ("futex: Remove duplicated code and fix undefined behaviour") Signed-off-by: NJiri Slaby <jslaby@suse.cz> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <dvhart@infradead.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Greg Kroah-Hartman 提交于
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org> Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com> Reviewed-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
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由 Daniel Borkmann 提交于
Follow-up to 0fd4759c ("bpf: fix pattern matches for direct packet access") to cover also the remaining data_meta/data matches in the verifier. The matches are also refactored a bit to simplify handling of all the cases. Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NJohn Fastabend <john.fastabend@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Daniel Borkmann 提交于
Two minor cleanups after Dave's recent merge in f8ddadc4 ("Merge git://git.kernel.org...") of net into net-next in order to get the code in line with what was done originally in the net tree: i) use max() instead of max_t() since both ranges are u16, ii) don't split the direct access test cases in the middle with bpf_exit test cases from 390ee7e2 ("bpf: enforce return code for cgroup-bpf programs"). Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NJohn Fastabend <john.fastabend@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Jesper Dangaard Brouer 提交于
Discovered that the compiler laid-out asm code in suboptimal way when studying perf report during benchmarking of cpumap. Help the compiler by the marking unlikely code paths. Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com> Acked-by: NJohn Fastabend <john.fastabend@gmail.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Andrew Clayton 提交于
Commit cc731525 ("signal: Remove kernel interal si_code magic") added a check for SIGMET and NSIGEMT being defined. That SIGMET should in fact be SIGEMT, with SIGEMT being defined in arch/{alpha,mips,sparc}/include/uapi/asm/signal.h This was actually pointed out by BenHutchings in a lwn.net comment here https://lwn.net/Comments/734608/ Fixes: cc731525 ("signal: Remove kernel interal si_code magic") Signed-off-by: NAndrew Clayton <andrew@digital-domain.net> Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
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由 Don Zickus 提交于
Guenter reported: There is still a problem. When running echo 6 > /proc/sys/kernel/watchdog_thresh echo 5 > /proc/sys/kernel/watchdog_thresh repeatedly, the message NMI watchdog: Enabled. Permanently consumes one hw-PMU counter. stops after a while (after ~10-30 iterations, with fluctuations). Maybe watchdog_cpus needs to be atomic ? That's correct as this again is affected by the asynchronous nature of the smpboot thread unpark mechanism. CPU 0 CPU1 CPU2 write(watchdog_thresh, 6) stop() park() update() start() unpark() thread->unpark() cnt++; write(watchdog_thresh, 5) thread->unpark() stop() park() thread->park() cnt--; cnt++; update() start() unpark() That's not a functional problem, it just affects the informational message. Convert watchdog_cpus to atomic_t to prevent the problem Reported-and-tested-by: NGuenter Roeck <linux@roeck-us.net> Signed-off-by: NDon Zickus <dzickus@redhat.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lkml.kernel.org/r/20171101181126.j727fqjmdthjz4xk@redhat.com
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由 Thomas Gleixner 提交于
watchdog/harclockup/perf: Revert a33d4484 ("watchdog/hardlockup/perf: Simplify deferred event destroy") Guenter reported a crash in the watchdog/perf code, which is caused by cleanup() and enable() running concurrently. The reason for this is: The watchdog functions are serialized via the watchdog_mutex and cpu hotplug locking, but the enable of the perf based watchdog happens in context of the unpark callback of the smpboot thread. But that unpark function is not synchronous inside the locking. The unparking of the thread just wakes it up and leaves so there is no guarantee when the thread is executing. If it starts running _before_ the cleanup happened then it will create a event and overwrite the dead event pointer. The new event is then cleaned up because the event is marked dead. lock(watchdog_mutex); lockup_detector_reconfigure(); cpus_read_lock(); stop(); park() update(); start(); unpark() cpus_read_unlock(); thread runs() overwrite dead event ptr cleanup(); free new event, which is active inside perf.... unlock(watchdog_mutex); The park side is safe as that actually waits for the thread to reach parked state. Commit a33d4484 removed the protection against this kind of scenario under the stupid assumption that the hotplug serialization and the watchdog_mutex cover everything. Bring it back. Reverts: a33d4484 ("watchdog/hardlockup/perf: Simplify deferred event destroy") Reported-and-tested-by: NGuenter Roeck <linux@roeck-us.net> Signed-off-by: NThomas Feels-stupid Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Don Zickus <dzickus@redhat.com> Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1710312145190.1942@nanos
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- 01 11月, 2017 5 次提交
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由 Alexei Starovoitov 提交于
fix verifier memory leaks Fixes: 638f5b90 ("bpf: reduce verifier memory consumption") Signed-off-by: NAlexei Starovoitov <ast@fb.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Peter Zijlstra 提交于
Dmitry (through syzbot) reported being able to trigger the WARN in get_pi_state() and a use-after-free on: raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); Both are due to this race: exit_pi_state_list() put_pi_state() lock(&curr->pi_lock) while() { pi_state = list_first_entry(head); hb = hash_futex(&pi_state->key); unlock(&curr->pi_lock); dec_and_test(&pi_state->refcount); lock(&hb->lock) lock(&pi_state->pi_mutex.wait_lock) // uaf if pi_state free'd lock(&curr->pi_lock); .... unlock(&curr->pi_lock); get_pi_state(); // WARN; refcount==0 The problem is we take the reference count too late, and don't allow it being 0. Fix it by using inc_not_zero() and simply retrying the loop when we fail to get a refcount. In that case put_pi_state() should remove the entry from the list. Reported-by: NDmitry Vyukov <dvyukov@google.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: NThomas Gleixner <tglx@linutronix.de> Cc: Gratian Crisan <gratian.crisan@ni.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: dvhart@infradead.org Cc: syzbot <bot+2af19c9e1ffe4d4ee1d16c56ae7580feaee75765@syzkaller.appspotmail.com> Cc: syzkaller-bugs@googlegroups.com Cc: <stable@vger.kernel.org> Fixes: c74aef2d ("futex: Fix pi_state->owner serialization") Link: http://lkml.kernel.org/r/20171031101853.xpfh72y643kdfhjs@hirez.programming.kicks-ass.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Yonghong Song 提交于
During perf event attaching/detaching bpf programs, the tp_event->prog_array change is protected by the bpf_event_mutex lock in both attaching and deteching functions. Although tp_event->prog_array is a rcu pointer, rcu_derefrence is not needed to access it since mutex lock will guarantee ordering. Verified through "make C=2" that sparse locking check still happy with the new change. Also change the label name in perf_event_{attach,detach}_bpf_prog from "out" to "unlock" to reflect the code action after the label. Signed-off-by: NYonghong Song <yhs@fb.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NMartin KaFai Lau <kafai@fb.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 John Fastabend 提交于
Now that SK_REDIRECT is no longer a valid return code. Remove it from the UAPI completely. Then do a namespace remapping internal to sockmap so SK_REDIRECT is no longer externally visible. Patchs primary change is to do a namechange from SK_REDIRECT to __SK_REDIRECT Reported-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Alexei Starovoitov 提交于
the verifier got progressively smarter over time and size of its internal state grew as well. Time to reduce the memory consumption. Before: sizeof(struct bpf_verifier_state) = 6520 After: sizeof(struct bpf_verifier_state) = 896 It's done by observing that majority of BPF programs use little to no stack whereas verifier kept all of 512 stack slots ready always. Instead dynamically reallocate struct verifier state when stack access is detected. Runtime difference before vs after is within a noise. The number of processed instructions stays the same. Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NDaniel Borkmann <daniel@iogearbox.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 30 10月, 2017 2 次提交
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由 Li Bin 提交于
When queue_work() is used in irq (not in task context), there is a potential case that trigger NULL pointer dereference. ---------------------------------------------------------------- worker_thread() |-spin_lock_irq() |-process_one_work() |-worker->current_pwq = pwq |-spin_unlock_irq() |-worker->current_func(work) |-spin_lock_irq() |-worker->current_pwq = NULL |-spin_unlock_irq() //interrupt here |-irq_handler |-__queue_work() //assuming that the wq is draining |-is_chained_work(wq) |-current_wq_worker() //Here, 'current' is the interrupted worker! |-current->current_pwq is NULL here! |-schedule() ---------------------------------------------------------------- Avoid it by checking for task context in current_wq_worker(), and if not in task context, we shouldn't use the 'current' to check the condition. Reported-by: NXiaofei Tan <tanxiaofei@huawei.com> Signed-off-by: NLi Bin <huawei.libin@huawei.com> Reviewed-by: NLai Jiangshan <jiangshanlai@gmail.com> Signed-off-by: NTejun Heo <tj@kernel.org> Fixes: 8d03ecfe ("workqueue: reimplement is_chained_work() using current_wq_worker()") Cc: stable@vger.kernel.org # v3.9+
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由 Tejun Heo 提交于
The following commit: 864c2357 ("perf/core: Do not set cpuctx->cgrp for unscheduled cgroups") made list_update_cgroup_event() skip setting cpuctx->cgrp if no cgroup event targets %current's cgroup. This breaks perf_event's hierarchical support because events which target one of the ancestors get ignored. Fix it by using cgroup_is_descendant() test instead of equality. Signed-off-by: NTejun Heo <tj@kernel.org> Acked-by: NThomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: David Carrillo-Cisneros <davidcc@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: kernel-team@fb.com Cc: stable@vger.kernel.org # v4.9+ Fixes: 864c2357 ("perf/core: Do not set cpuctx->cgrp for unscheduled cgroups") Link: http://lkml.kernel.org/r/20171028164237.GA972780@devbig577.frc2.facebook.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 29 10月, 2017 2 次提交
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由 John Fastabend 提交于
Recent additions to support multiple programs in cgroups impose a strict requirement, "all yes is yes, any no is no". To enforce this the infrastructure requires the 'no' return code, SK_DROP in this case, to be 0. To apply these rules to SK_SKB program types the sk_actions return codes need to be adjusted. This fix adds SK_PASS and makes 'SK_DROP = 0'. Finally, remove SK_ABORTED to remove any chance that the API may allow aborted program flows to be passed up the stack. This would be incorrect behavior and allow programs to break existing policies. Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 John Fastabend 提交于
SK_SKB program types use bpf_compute_data to store the end of the packet data. However, bpf_compute_data assumes the cb is stored in the qdisc layer format. But, for SK_SKB this is the wrong layer of the stack for this type. It happens to work (sort of!) because in most cases nothing happens to be overwritten today. This is very fragile and error prone. Fortunately, we have another hole in tcp_skb_cb we can use so lets put the data_end value there. Note, SK_SKB program types do not use data_meta, they are failed by sk_skb_is_valid_access(). Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 27 10月, 2017 1 次提交
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由 Gianluca Borello 提交于
commit afdb09c7 ("security: bpf: Add LSM hooks for bpf object related syscall") included linux/bpf.h in linux/security.h. As a result, bpf programs including bpf_helpers.h and some other header that ends up pulling in also security.h, such as several examples under samples/bpf, fail to compile because bpf_tail_call and bpf_get_stackid are now "redefined as different kind of symbol". >From bpf.h: u64 bpf_tail_call(u64 ctx, u64 r2, u64 index, u64 r4, u64 r5); u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); Whereas in bpf_helpers.h they are: static void (*bpf_tail_call)(void *ctx, void *map, int index); static int (*bpf_get_stackid)(void *ctx, void *map, int flags); Fix this by removing the unused declaration of bpf_tail_call and moving the declaration of bpf_get_stackid in bpf_trace.c, which is the only place where it's needed. Signed-off-by: NGianluca Borello <g.borello@gmail.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 25 10月, 2017 2 次提交
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由 Yonghong Song 提交于
This patch enables multiple bpf attachments for a kprobe/uprobe/tracepoint single trace event. Each trace_event keeps a list of attached perf events. When an event happens, all attached bpf programs will be executed based on the order of attachment. A global bpf_event_mutex lock is introduced to protect prog_array attaching and detaching. An alternative will be introduce a mutex lock in every trace_event_call structure, but it takes a lot of extra memory. So a global bpf_event_mutex lock is a good compromise. The bpf prog detachment involves allocation of memory. If the allocation fails, a dummy do-nothing program will replace to-be-detached program in-place. Signed-off-by: NYonghong Song <yhs@fb.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NMartin KaFai Lau <kafai@fb.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Yonghong Song 提交于
This is a cleanup such that doing the same check in perf_event_free_bpf_prog as we already do in perf_event_set_bpf_prog step. Signed-off-by: NYonghong Song <yhs@fb.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NMartin KaFai Lau <kafai@fb.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 24 10月, 2017 1 次提交
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由 Jesper Dangaard Brouer 提交于
As pointed out by Michael, commit 1c601d82 ("bpf: cpumap xdp_buff to skb conversion and allocation") contains a classical example of the potential lost wake-up problem. We need to recheck the condition __ptr_ring_empty() after changing current->state to TASK_INTERRUPTIBLE, this avoids a race between wake_up_process() and schedule(). After this, a race with wake_up_process() will simply change the state to TASK_RUNNING, and the schedule() call not really put us to sleep. Fixes: 1c601d82 ("bpf: cpumap xdp_buff to skb conversion and allocation") Reported-by: N"Michael S. Tsirkin" <mst@redhat.com> Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 22 10月, 2017 3 次提交
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由 Daniel Borkmann 提交于
Alexander had a test program with direct packet access, where the access test was in the form of data + X > data_end. In an unrelated change to the program LLVM decided to swap the branches and emitted code for the test in form of data + X <= data_end. We hadn't seen these being generated previously, thus verifier would reject the program. Therefore, fix up the verifier to detect all test cases, so we don't run into such issues in the future. Fixes: b4e432f1 ("bpf: enable BPF_J{LT, LE, SLT, SLE} opcodes in verifier") Reported-by: NAlexander Alemayhu <alexander@alemayhu.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NJohn Fastabend <john.fastabend@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Daniel Borkmann 提交于
During review I noticed that the current logic for direct packet access marking in check_cond_jmp_op() has an off by one for the upper right range border when marking in find_good_pkt_pointers() with BPF_JLT and BPF_JLE. It's not really harmful given access up to pkt_end is always safe, but we should nevertheless correct the range marking before it becomes ABI. If pkt_data' denotes a pkt_data derived pointer (pkt_data + X), then for pkt_data' < pkt_end in the true branch as well as for pkt_end <= pkt_data' in the false branch we mark the range with X although it should really be X - 1 in these cases. For example, X could be pkt_end - pkt_data, then when testing for pkt_data' < pkt_end the verifier simulation cannot deduce that a byte load of pkt_data' - 1 would succeed in this branch. Fixes: b4e432f1 ("bpf: enable BPF_J{LT, LE, SLT, SLE} opcodes in verifier") Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NJohn Fastabend <john.fastabend@gmail.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 John Fastabend 提交于
An integer overflow is possible in dev_map_bitmap_size() when calculating the BITS_TO_LONG logic which becomes, after macro replacement, (((n) + (d) - 1)/ (d)) where 'n' is a __u32 and 'd' is (8 * sizeof(long)). To avoid overflow cast to u64 before arithmetic. Reported-by: NRichard Weinberger <richard@nod.at> Acked-by: NDaniel Borkmann <daniel@iogearbox.net> Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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- 21 10月, 2017 2 次提交
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由 Thomas Gleixner 提交于
The recent rework of the cpu hotplug internals changed the usage of the per cpu state->node field, but missed to clean it up after usage. So subsequent hotplug operations use the stale pointer from a previous operation and hand it into the callback functions. The callbacks then dereference a pointer which either belongs to a different facility or points to freed and potentially reused memory. In either case data corruption and crashes are the obvious consequence. Reset the node and the last pointers in the per cpu state to NULL after the operation which set them has completed. Fixes: 96abb968 ("smp/hotplug: Allow external multi-instance rollback") Reported-by: NTvrtko Ursulin <tursulin@ursulin.net> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Link: https://lkml.kernel.org/r/alpine.DEB.2.20.1710211606130.3213@nanos
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由 Kees Cook 提交于
As pointed out by Linus and David, the earlier waitid() fix resulted in a (currently harmless) unbalanced user_access_end() call. This fixes it to just directly return EFAULT on access_ok() failure. Fixes: 96ca579a ("waitid(): Add missing access_ok() checks") Acked-by: NDavid Daney <david.daney@cavium.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: NKees Cook <keescook@chromium.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 20 10月, 2017 3 次提交
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由 Chenbo Feng 提交于
Introduce a bpf object related check when sending and receiving files through unix domain socket as well as binder. It checks if the receiving process have privilege to read/write the bpf map or use the bpf program. This check is necessary because the bpf maps and programs are using a anonymous inode as their shared inode so the normal way of checking the files and sockets when passing between processes cannot work properly on eBPF object. This check only works when the BPF_SYSCALL is configured. Signed-off-by: NChenbo Feng <fengc@google.com> Acked-by: NStephen Smalley <sds@tycho.nsa.gov> Reviewed-by: NJames Morris <james.l.morris@oracle.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Chenbo Feng 提交于
Introduce several LSM hooks for the syscalls that will allow the userspace to access to eBPF object such as eBPF programs and eBPF maps. The security check is aimed to enforce a per object security protection for eBPF object so only processes with the right priviliges can read/write to a specific map or use a specific eBPF program. Besides that, a general security hook is added before the multiplexer of bpf syscall to check the cmd and the attribute used for the command. The actual security module can decide which command need to be checked and how the cmd should be checked. Signed-off-by: NChenbo Feng <fengc@google.com> Acked-by: NJames Morris <james.l.morris@oracle.com> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Chenbo Feng 提交于
Introduce the map read/write flags to the eBPF syscalls that returns the map fd. The flags is used to set up the file mode when construct a new file descriptor for bpf maps. To not break the backward capability, the f_flags is set to O_RDWR if the flag passed by syscall is 0. Otherwise it should be O_RDONLY or O_WRONLY. When the userspace want to modify or read the map content, it will check the file mode to see if it is allowed to make the change. Signed-off-by: NChenbo Feng <fengc@google.com> Acked-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NDaniel Borkmann <daniel@iogearbox.net> Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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