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2019-04-30mm/hibernation: Make hibernation handle unmapped pagesRick Edgecombe4-20/+14
Make hibernate handle unmapped pages on the direct map when CONFIG_ARCH_HAS_SET_ALIAS=y is set. These functions allow for setting pages to invalid configurations, so now hibernate should check if the pages have valid mappings and handle if they are unmapped when doing a hibernate save operation. Previously this checking was already done when CONFIG_DEBUG_PAGEALLOC=y was configured. It does not appear to have a big hibernating performance impact. The speed of the saving operation before this change was measured as 819.02 MB/s, and after was measured at 813.32 MB/s. Before: [ 4.670938] PM: Wrote 171996 kbytes in 0.21 seconds (819.02 MB/s) After: [ 4.504714] PM: Wrote 178932 kbytes in 0.22 seconds (813.32 MB/s) Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Rafael J. Wysocki <rjw@rjwysocki.net> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-16-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30x86/mm/cpa: Add set_direct_map_*() functionsRick Edgecombe5-3/+30
Add two new functions set_direct_map_default_noflush() and set_direct_map_invalid_noflush() for setting the direct map alias for the page to its default valid permissions and to an invalid state that cannot be cached in a TLB, respectively. These functions do not flush the TLB. Note, __kernel_map_pages() does something similar but flushes the TLB and doesn't reset the permission bits to default on all architectures. Also add an ARCH config ARCH_HAS_SET_DIRECT_MAP for specifying whether these have an actual implementation or a default empty one. Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Nadav Amit <nadav.amit@gmail.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-15-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30x86/alternatives: Remove the return value of text_poke_*()Nadav Amit2-9/+6
The return value of text_poke_early() and text_poke_bp() is useless. Remove it. Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-14-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30x86/jump-label: Remove support for custom text pokerNadav Amit1-16/+10
There are only two types of text poking: early and breakpoint based. The use of a function pointer to perform text poking complicates the code and is probably inefficient due to the use of indirect branches. Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-13-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30x86/modules: Avoid breaking W^X while loading modulesNadav Amit4-8/+28
When modules and BPF filters are loaded, there is a time window in which some memory is both writable and executable. An attacker that has already found another vulnerability (e.g., a dangling pointer) might be able to exploit this behavior to overwrite kernel code. Prevent having writable executable PTEs in this stage. In addition, avoiding having W+X mappings can also slightly simplify the patching of modules code on initialization (e.g., by alternatives and static-key), as would be done in the next patch. This was actually the main motivation for this patch. To avoid having W+X mappings, set them initially as RW (NX) and after they are set as RO set them as X as well. Setting them as executable is done as a separate step to avoid one core in which the old PTE is cached (hence writable), and another which sees the updated PTE (executable), which would break the W^X protection. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Suggested-by: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jessica Yu <jeyu@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Rik van Riel <riel@surriel.com> Link: https://lkml.kernel.org/r/20190426001143.4983-12-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30x86/kprobes: Set instruction page as executableNadav Amit1-4/+20
Set the page as executable after allocation. This patch is a preparatory patch for a following patch that makes module allocated pages non-executable. While at it, do some small cleanup of what appears to be unnecessary masking. Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-11-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30x86/ftrace: Set trampoline pages as executableNadav Amit1-0/+8
Since alloc_module() will not set the pages as executable soon, set ftrace trampoline pages as executable after they are allocated. For the time being, do not change ftrace to use the text_poke() interface. As a result, ftrace still breaks W^X. Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-10-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30x86/kgdb: Avoid redundant comparison of patched codeNadav Amit1-13/+1
text_poke() already ensures that the written value is the correct one and fails if that is not the case. There is no need for an additional comparison. Remove it. Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-9-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30x86/alternatives: Use temporary mm for text pokingNadav Amit3-26/+86
text_poke() can potentially compromise security as it sets temporary PTEs in the fixmap. These PTEs might be used to rewrite the kernel code from other cores accidentally or maliciously, if an attacker gains the ability to write onto kernel memory. Moreover, since remote TLBs are not flushed after the temporary PTEs are removed, the time-window in which the code is writable is not limited if the fixmap PTEs - maliciously or accidentally - are cached in the TLB. To address these potential security hazards, use a temporary mm for patching the code. Finally, text_poke() is also not conservative enough when mapping pages, as it always tries to map 2 pages, even when a single one is sufficient. So try to be more conservative, and do not map more than needed. Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-8-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30x86/alternatives: Initialize temporary mm for patchingNadav Amit5-0/+48
To prevent improper use of the PTEs that are used for text patching, the next patches will use a temporary mm struct. Initailize it by copying the init mm. The address that will be used for patching is taken from the lower area that is usually used for the task memory. Doing so prevents the need to frequently synchronize the temporary-mm (e.g., when BPF programs are installed), since different PGDs are used for the task memory. Finally, randomize the address of the PTEs to harden against exploits that use these PTEs. Suggested-by: Andy Lutomirski <luto@kernel.org> Tested-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: ard.biesheuvel@linaro.org Cc: deneen.t.dock@intel.com Cc: kernel-hardening@lists.openwall.com Cc: kristen@linux.intel.com Cc: linux_dti@icloud.com Cc: will.deacon@arm.com Link: https://lkml.kernel.org/r/20190426232303.28381-8-nadav.amit@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30fork: Provide a function for copying init_mmNadav Amit2-6/+19
Provide a function for copying init_mm. This function will be later used for setting a temporary mm. Tested-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-6-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30uprobes: Initialize uprobes earlierNadav Amit3-5/+9
In order to have a separate address space for text poking, we need to duplicate init_mm early during start_kernel(). This, however, introduces a problem since uprobes functions are called from dup_mmap(), but uprobes is still not initialized in this early stage. Since uprobes initialization is necassary for fork, and since all the dependant initialization has been done when fork is initialized (percpu and vmalloc), move uprobes initialization to fork_init(). It does not seem uprobes introduces any security problem for the poking_mm. Crash and burn if uprobes initialization fails, similarly to other early initializations. Change the init_probes() name to probes_init() to match other early initialization functions name convention. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rick Edgecombe <rick.p.edgecombe@intel.com> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akpm@linux-foundation.org Cc: ard.biesheuvel@linaro.org Cc: deneen.t.dock@intel.com Cc: kernel-hardening@lists.openwall.com Cc: kristen@linux.intel.com Cc: linux_dti@icloud.com Cc: will.deacon@arm.com Link: https://lkml.kernel.org/r/20190426232303.28381-6-nadav.amit@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30x86/mm: Save debug registers when loading a temporary mmNadav Amit1-0/+23
Prevent user watchpoints from mistakenly firing while the temporary mm is being used. As the addresses of the temporary mm might overlap those of the user-process, this is necessary to prevent wrong signals or worse things from happening. Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-5-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30x86/mm: Introduce temporary mm structsAndy Lutomirski1-0/+33
Using a dedicated page-table for temporary PTEs prevents other cores from using - even speculatively - these PTEs, thereby providing two benefits: (1) Security hardening: an attacker that gains kernel memory writing abilities cannot easily overwrite sensitive data. (2) Avoiding TLB shootdowns: the PTEs do not need to be flushed in remote page-tables. To do so a temporary mm_struct can be used. Mappings which are private for this mm can be set in the userspace part of the address-space. During the whole time in which the temporary mm is loaded, interrupts must be disabled. The first use-case for temporary mm struct, which will follow, is for poking the kernel text. [ Commit message was written by Nadav Amit ] Tested-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-4-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30x86/jump_label: Use text_poke_early() during early initNadav Amit1-1/+6
There is no apparent reason not to use text_poke_early() during early-init, since no patching of code that might be on the stack is done and only a single core is running. This is required for the next patches that would set a temporary mm for text poking, and this mm is only initialized after some static-keys are enabled/disabled. Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-3-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30bpf: Fail bpf_probe_write_user() while mm is switchedNadav Amit1-0/+8
When using a temporary mm, bpf_probe_write_user() should not be able to write to user memory, since user memory addresses may be used to map kernel memory. Detect these cases and fail bpf_probe_write_user() in such cases. Suggested-by: Jann Horn <jannh@google.com> Reported-by: Jann Horn <jannh@google.com> Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-24-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30mm/tlb: Provide default nmi_uaccess_okay()Nadav Amit2-0/+11
x86 has an nmi_uaccess_okay(), but other architectures do not. Arch-independent code might need to know whether access to user addresses is ok in an NMI context or in other code whose execution context is unknown. Specifically, this function is needed for bpf_probe_write_user(). Add a default implementation of nmi_uaccess_okay() for architectures that do not have such a function. Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20190426001143.4983-23-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30x86/alternatives: Add text_poke_kgdb() to not assert the lock when debuggingNadav Amit3-19/+45
text_mutex is currently expected to be held before text_poke() is called, but kgdb does not take the mutex, and instead *supposedly* ensures the lock is not taken and will not be acquired by any other core while text_poke() is running. The reason for the "supposedly" comment is that it is not entirely clear that this would be the case if gdb_do_roundup is zero. Create two wrapper functions, text_poke() and text_poke_kgdb(), which do or do not run the lockdep assertion respectively. While we are at it, change the return code of text_poke() to something meaningful. One day, callers might actually respect it and the existing BUG_ON() when patching fails could be removed. For kgdb, the return value can actually be used. Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Nadav Amit <namit@vmware.com> Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Jiri Kosina <jkosina@suse.cz> Cc: <akpm@linux-foundation.org> Cc: <ard.biesheuvel@linaro.org> Cc: <deneen.t.dock@intel.com> Cc: <kernel-hardening@lists.openwall.com> Cc: <kristen@linux.intel.com> Cc: <linux_dti@icloud.com> Cc: <will.deacon@arm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@surriel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 9222f606506c ("x86/alternatives: Lockdep-enforce text_mutex in text_poke*()") Link: https://lkml.kernel.org/r/20190426001143.4983-2-namit@vmware.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-30Merge tag 'v5.1-rc7' into x86/mm, to pick up fixesIngo Molnar60-224/+404
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-04-29Linux 5.1-rc7Linus Torvalds1-1/+1
2019-04-28Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-armLinus Torvalds4-6/+20
Pull ARM fixes from Russell King: "A small number of ARM fixes - Fix function tracer and unwinder dependencies so that we don't end up building kernels that will crash - Fix ARMv7M nommu initialisation (missing register initialisation) - Fix EFI decompressor entry (ensuring barrier instructions are enabled prior to use)" * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: 8857/1: efi: enable CP15 DMB instructions before cleaning the cache ARM: 8856/1: NOMMU: Fix CCR register faulty initialization when MPU is disabled ARM: fix function graph tracer and unwinder dependencies
2019-04-28Merge tag 'powerpc-5.1-6' of ↵Linus Torvalds3-40/+60
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "A one-liner to make our Radix MMU support depend on HUGETLB_PAGE. We use some of the hugetlb inlines (eg. pud_huge()) when operating on the linear mapping and if they're compiled into empty wrappers we can corrupt memory. Then two fixes to our VFIO IOMMU code. The first is not a regression but fixes the locking to avoid a user-triggerable deadlock. The second does fix a regression since rc1, and depends on the first fix. It makes it possible to run guests with large amounts of memory again (~256GB). Thanks to Alexey Kardashevskiy" * tag 'powerpc-5.1-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/mm_iommu: Allow pinning large regions powerpc/mm_iommu: Fix potential deadlock powerpc/mm/radix: Make Radix require HUGETLB_PAGE
2019-04-28Merge tag 'for-linus-20190428' of git://git.kernel.dk/linux-blockLinus Torvalds1-16/+26
Pull block fixes from Jens Axboe: "A set of io_uring fixes that should go into this release. In particular, this contains: - The mutex lock vs ctx ref count fix (me) - Removal of a dead variable (me) - Two race fixes (Stefan) - Ring head/tail condition fix for poll full SQ detection (Stefan)" * tag 'for-linus-20190428' of git://git.kernel.dk/linux-block: io_uring: remove 'state' argument from io_{read,write} path io_uring: fix poll full SQ detection io_uring: fix race condition when sq threads goes sleeping io_uring: fix race condition reading SQ entries io_uring: fail io_uring_register(2) on a dying io_uring instance
2019-04-28Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdmaLinus Torvalds7-20/+76
Pull rdma fixes from Jason Gunthorpe: "One core bug fix and a few driver ones - FRWR memory registration for hfi1/qib didn't work with with some iovas causing a NFSoRDMA failure regression due to a fix in the NFS side - A command flow error in mlx5 allowed user space to send a corrupt command (and also smash the kernel stack we've since learned) - Fix a regression and some bugs with device hot unplug that was discovered while reviewing Andrea's patches - hns has a failure if the user asks for certain QP configurations" * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: RDMA/hns: Bugfix for mapping user db RDMA/ucontext: Fix regression with disassociate RDMA/mlx5: Use rdma_user_map_io for mapping BAR pages RDMA/mlx5: Do not allow the user to write to the clock page IB/mlx5: Fix scatter to CQE in DCT QP creation IB/rdmavt: Fix frwr memory registration
2019-04-28Merge tag 'dmaengine-fix-5.1-rc7' of ↵Linus Torvalds3-6/+28
git://git.infradead.org/users/vkoul/slave-dma Pull dmaengine fixes from Vinod Koul: - fix for wrong register use in mediatek driver - fix in sh driver for glitch is tx_status and treating 0 a valid residue for cyclic - fix in bcm driver for using right memory allocation flag * tag 'dmaengine-fix-5.1-rc7' of git://git.infradead.org/users/vkoul/slave-dma: dmaengine: mediatek-cqdma: fix wrong register usage in mtk_cqdma_start dmaengine: sh: rcar-dmac: Fix glitch in dmaengine_tx_status dmaengine: sh: rcar-dmac: With cyclic DMA residue 0 is valid dmaengine: bcm2835: Avoid GFP_KERNEL in device_prep_slave_sg
2019-04-28Merge branch 'for-linus' of ↵Linus Torvalds3-7/+3
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input Pull input fixes from Dmitry Torokhov: "Just a couple of fixups for Synaptics RMI4 driver and allowing snvs_pwrkey to be selected on more boards" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: synaptics-rmi4 - write config register values to the right offset Input: synaptics-rmi4 - fix possible double free Input: snvs_pwrkey - make it depend on ARCH_MXC
2019-04-27Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds2-1/+7
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: - Fix an early boot crash in the RSDP parsing code by effectively turning off the parsing call - we ran out of time but want to fix the regression. The more involved fix is being worked on. - Fix a crash that can trigger in the kmemlek code. * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Fix a crash with kmemleak_scan() x86/boot: Disable RSDP parsing temporarily
2019-04-27Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds1-0/+4
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Ingo Molnar: "Fix a division by zero bug that can trigger in the NUMA placement code" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/numa: Fix a possible divide-by-zero
2019-04-27Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds1-5/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fix from Ingo Molnar: "A cstate event enumeration fix for Kaby/Coffee Lake CPUs" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Update KBL Package C-state events to also include PC8/PC9/PC10 counters
2019-04-27slip: make slhc_free() silently accept an error pointerLinus Torvalds1-1/+1
This way, slhc_free() accepts what slhc_init() returns, whether that is an error or not. In particular, the pattern in sl_alloc_bufs() is slcomp = slhc_init(16, 16); ... slhc_free(slcomp); for the error handling path, and rather than complicate that code, just make it ok to always free what was returned by the init function. That's what the code used to do before commit 4ab42d78e37a ("ppp, slip: Validate VJ compression slot parameters completely") when slhc_init() just returned NULL for the error case, with no actual indication of the details of the error. Reported-by: syzbot+45474c076a4927533d2e@syzkaller.appspotmail.com Fixes: 4ab42d78e37a ("ppp, slip: Validate VJ compression slot parameters completely") Acked-by: Ben Hutchings <ben@decadent.org.uk> Cc: David Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-27Merge branch 'akpm' (patches from Andrew)Linus Torvalds7-23/+39
Merge misc fixes from Andrew Morton: "9 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: fs/proc/proc_sysctl.c: Fix a NULL pointer dereference mm/page_alloc.c: fix never set ALLOC_NOFRAGMENT flag mm/page_alloc.c: avoid potential NULL pointer dereference mm, page_alloc: always use a captured page regardless of compaction result mm: do not boost watermarks to avoid fragmentation for the DISCONTIG memory model lib/test_vmalloc.c: do not create cpumask_t variable on stack lib/Kconfig.debug: fix build error without CONFIG_BLOCK zram: pass down the bvec we need to read into in the work struct mm/memory_hotplug.c: drop memory device reference after find_memory_block()
2019-04-27Input: synaptics-rmi4 - write config register values to the right offsetLucas Stach1-1/+1
Currently any changed config register values don't take effect, as the function to write them back is called with the wrong register offset. Fixes: ff8f83708b3e (Input: synaptics-rmi4 - add support for 2D sensors and F11) Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2019-04-26Merge tag 'arm64-fixes' of ↵Linus Torvalds2-3/+8
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Catalin Marinas: - keep the tail of an unaligned initrd reserved - adjust ftrace_make_call() to deal with the relative nature of PLTs * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64/module: ftrace: deal with place relative nature of PLTs arm64: mm: Ensure tail of unaligned initrd is reserved
2019-04-26Merge tag 'trace-v5.1-rc6' of ↵Linus Torvalds4-19/+23
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Three tracing fixes: - Use "nosteal" for ring buffer splice pages - Memory leak fix in error path of trace_pid_write() - Fix preempt_enable_no_resched() (use preempt_enable()) in ring buffer code" * tag 'trace-v5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: trace: Fix preempt_enable_no_resched() abuse tracing: Fix a memory leak by early error exit in trace_pid_write() tracing: Fix buffer_ref pipe ops
2019-04-26Merge tag 'gpio-v5.1-3' of ↵Linus Torvalds2-4/+9
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio Pull GPIO fixes from Linus Walleij: "Not much to say about them, regular fixes: - Fix a bug on the errorpath of gpiochip_add_data_with_key() - IRQ type setting on the spreadtrum GPIO driver" * tag 'gpio-v5.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: gpio: Fix gpiochip_add_data_with_key() error path gpio: eic: sprd: Fix incorrect irq type setting for the sync EIC
2019-04-26Merge tag 'drm-fixes-2019-04-26' of git://anongit.freedesktop.org/drm/drmLinus Torvalds12-52/+53
Pull drm fixes from Dave Airlie: "Regular drm fixes, nothing too outstanding, I'm guessing Easter was slowing people down. i915: - FEC enable fix - BXT display lanes fix ttm: - fix reinit for reloading drivers regression imx: - DP CSC fix sun4i: - module unload/load fix vc4: - memory leak fix - compile fix dw-hdmi: - rockchip scdc overflow fix sched: - docs fix vmwgfx: - dma api layering fix" * tag 'drm-fixes-2019-04-26' of git://anongit.freedesktop.org/drm/drm: drm/bridge: dw-hdmi: fix SCDC configuration for ddc-i2c-bus drm/vmwgfx: Fix dma API layer violation drm/vc4: Fix compilation error reported by kbuild test bot drm/sun4i: Unbind components before releasing DRM and memory drm/vc4: Fix memory leak during gpu reset. drm/sched: Fix description of drm_sched_stop drm/imx: don't skip DP channel disable for background plane gpu: ipu-v3: dp: fix CSC handling drm/ttm: fix re-init of global structures drm/sun4i: Fix component unbinding and component master deletion drm/sun4i: Set device driver data at bind time for use in unbind drm/sun4i: Add missing drm_atomic_helper_shutdown at driver unbind drm/i915: Restore correct bxt_ddi_phy_calc_lane_lat_optim_mask() calculation drm/i915: Do not enable FEC without DSC drm: bridge: dw-hdmi: Fix overflow workaround for Rockchip SoCs
2019-04-26Merge tag 'for-5.1-rc6-tag' of ↵Linus Torvalds2-5/+13
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fix from David Sterba: "One patch to fix a crash in io submission path, due to memory allocation errors. In short, the multipage bio work that landed in 5.1 caused larger bios that in turn require larger temporary memory for checksums. The patch is a workaround, we're going to rework the allocation so it does not require the vmalloc fallback. It took a while to identify that it's caused by patches in 5.1 and not a patchset that did some changes in error handling in the code. I've tested it on various memory/cpu combinations, it could hit OOM but does not crash. The timestamp of the patch is less than a day due to updates in the changelog, tests were running meanwhile" * tag 'for-5.1-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: Switch memory allocations in async csum calculation path to kvmalloc
2019-04-26Merge tag '5.1-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds4-15/+28
Pull cifs fixes from Steve French: "Three small SMB3 fixes (all for stable as well): two leaks and a rename bug" * tag '5.1-rc6-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: cifs: fix page reference leak with readv/writev cifs: do not attempt cifs operation on smb2+ rename error cifs: fix memory leak in SMB2_read
2019-04-26fs/proc/proc_sysctl.c: Fix a NULL pointer dereferenceYueHaibing1-2/+4
Syzkaller report this: sysctl could not get directory: /net//bridge -12 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 PTI CPU: 1 PID: 7027 Comm: syz-executor.0 Tainted: G C 5.1.0-rc3+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 RIP: 0010:__write_once_size include/linux/compiler.h:220 [inline] RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:144 [inline] RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:186 [inline] RIP: 0010:rb_erase+0x5f4/0x19f0 lib/rbtree.c:459 Code: 00 0f 85 60 13 00 00 48 89 1a 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 89 f2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 75 0c 00 00 4d 85 ed 4c 89 2e 74 ce 4c 89 ea 48 RSP: 0018:ffff8881bb507778 EFLAGS: 00010206 RAX: dffffc0000000000 RBX: ffff8881f224b5b8 RCX: ffffffff818f3f6a RDX: 000000000000000a RSI: 0000000000000050 RDI: ffff8881f224b568 RBP: 0000000000000000 R08: ffffed10376a0ef4 R09: ffffed10376a0ef4 R10: 0000000000000001 R11: ffffed10376a0ef4 R12: ffff8881f224b558 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f3e7ce13700(0000) GS:ffff8881f7300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd60fbe9398 CR3: 00000001cb55c001 CR4: 00000000007606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: erase_entry fs/proc/proc_sysctl.c:178 [inline] erase_header+0xe3/0x160 fs/proc/proc_sysctl.c:207 start_unregistering fs/proc/proc_sysctl.c:331 [inline] drop_sysctl_table+0x558/0x880 fs/proc/proc_sysctl.c:1631 get_subdir fs/proc/proc_sysctl.c:1022 [inline] __register_sysctl_table+0xd65/0x1090 fs/proc/proc_sysctl.c:1335 br_netfilter_init+0x68/0x1000 [br_netfilter] do_one_initcall+0xbc/0x47d init/main.c:901 do_init_module+0x1b5/0x547 kernel/module.c:3456 load_module+0x6405/0x8c10 kernel/module.c:3804 __do_sys_finit_module+0x162/0x190 kernel/module.c:3898 do_syscall_64+0x9f/0x450 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Modules linked in: br_netfilter(+) backlight comedi(C) hid_sensor_hub max3100 ti_ads8688 udc_core fddi snd_mona leds_gpio rc_streamzap mtd pata_netcell nf_log_common rc_winfast udp_tunnel snd_usbmidi_lib snd_usb_toneport snd_usb_line6 snd_rawmidi snd_seq_device snd_hwdep videobuf2_v4l2 videobuf2_common videodev media videobuf2_vmalloc videobuf2_memops rc_gadmei_rm008z 8250_of smm665 hid_tmff hid_saitek hwmon_vid rc_ati_tv_wonder_hd_600 rc_core pata_pdc202xx_old dn_rtmsg as3722 ad714x_i2c ad714x snd_soc_cs4265 hid_kensington panel_ilitek_ili9322 drm drm_panel_orientation_quirks ipack cdc_phonet usbcore phonet hid_jabra hid extcon_arizona can_dev industrialio_triggered_buffer kfifo_buf industrialio adm1031 i2c_mux_ltc4306 i2c_mux ipmi_msghandler mlxsw_core snd_soc_cs35l34 snd_soc_core snd_pcm_dmaengine snd_pcm snd_timer ac97_bus snd_compress snd soundcore gpio_da9055 uio ecdh_generic mdio_thunder of_mdio fixed_phy libphy mdio_cavium iptable_security iptable_raw iptable_mangle iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_filter bpfilter ip6_vti ip_vti ip_gre ipip sit tunnel4 ip_tunnel hsr veth netdevsim vxcan batman_adv cfg80211 rfkill chnl_net caif nlmon dummy team bonding vcan bridge stp llc ip6_gre gre ip6_tunnel tunnel6 tun joydev mousedev ppdev tpm kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel ide_pci_generic piix aes_x86_64 crypto_simd cryptd ide_core glue_helper input_leds psmouse intel_agp intel_gtt serio_raw ata_generic i2c_piix4 agpgart pata_acpi parport_pc parport floppy rtc_cmos sch_fq_codel ip_tables x_tables sha1_ssse3 sha1_generic ipv6 [last unloaded: br_netfilter] Dumping ftrace buffer: (ftrace buffer empty) ---[ end trace 68741688d5fbfe85 ]--- commit 23da9588037e ("fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links") forgot to handle start_unregistering() case, while header->parent is NULL, it calls erase_header() and as seen in the above syzkaller call trace, accessing &header->parent->root will trigger a NULL pointer dereference. As that commit explained, there is also no need to call start_unregistering() if header->parent is NULL. Link: http://lkml.kernel.org/r/20190409153622.28112-1-yuehaibing@huawei.com Fixes: 23da9588037e ("fs/proc/proc_sysctl.c: fix NULL pointer dereference in put_links") Fixes: 0e47c99d7fe25 ("sysctl: Replace root_list with links between sysctl_table_sets") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reported-by: Hulk Robot <hulkci@huawei.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-26mm/page_alloc.c: fix never set ALLOC_NOFRAGMENT flagAndrey Ryabinin1-3/+3
Commit 0a79cdad5eb2 ("mm: use alloc_flags to record if kswapd can wake") removed setting of the ALLOC_NOFRAGMENT flag. Bring it back. The runtime effect is that ALLOC_NOFRAGMENT behaviour is restored so that allocations are spread across local zones to avoid fragmentation due to mixing pageblocks as long as possible. Link: http://lkml.kernel.org/r/20190423120806.3503-2-aryabinin@virtuozzo.com Fixes: 0a79cdad5eb2 ("mm: use alloc_flags to record if kswapd can wake") Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-26mm/page_alloc.c: avoid potential NULL pointer dereferenceAndrey Ryabinin1-0/+3
ac.preferred_zoneref->zone passed to alloc_flags_nofragment() can be NULL. 'zone' pointer unconditionally derefernced in alloc_flags_nofragment(). Bail out on NULL zone to avoid potential crash. Currently we don't see any crashes only because alloc_flags_nofragment() has another bug which allows compiler to optimize away all accesses to 'zone'. Link: http://lkml.kernel.org/r/20190423120806.3503-1-aryabinin@virtuozzo.com Fixes: 6bb154504f8b ("mm, page_alloc: spread allocations across zones before introducing fragmentation") Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-26mm, page_alloc: always use a captured page regardless of compaction resultMel Gorman1-5/+0
During the development of commit 5e1f0f098b46 ("mm, compaction: capture a page under direct compaction"), a paranoid check was added to ensure that if a captured page was available after compaction that it was consistent with the final state of compaction. The intent was to catch serious programming bugs such as using a stale page pointer and causing corruption problems. However, it is possible to get a captured page even if compaction was unsuccessful if an interrupt triggered and happened to free pages in interrupt context that got merged into a suitable high-order page. It's highly unlikely but Li Wang did report the following warning on s390 occuring when testing OOM handling. Note that the warning is slightly edited for clarity. WARNING: CPU: 0 PID: 9783 at mm/page_alloc.c:3777 __alloc_pages_direct_compact+0x182/0x190 Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache sunrpc pkey ghash_s390 prng xts aes_s390 des_s390 des_generic sha512_s390 zcrypt_cex4 zcrypt vmur binfmt_misc ip_tables xfs libcrc32c dasd_fba_mod qeth_l2 dasd_eckd_mod dasd_mod qeth qdio lcs ctcm ccwgroup fsm dm_mirror dm_region_hash dm_log dm_mod CPU: 0 PID: 9783 Comm: copy.sh Kdump: loaded Not tainted 5.1.0-rc 5 #1 This patch simply removes the check entirely instead of trying to be clever about pages freed from interrupt context. If a serious programming error was introduced, it is highly likely to be caught by prep_new_page() instead. Link: http://lkml.kernel.org/r/20190419085133.GH18914@techsingularity.net Fixes: 5e1f0f098b46 ("mm, compaction: capture a page under direct compaction") Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Li Wang <liwang@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-26mm: do not boost watermarks to avoid fragmentation for the DISCONTIG memory ↵Mel Gorman2-8/+21
model Mikulas Patocka reported that commit 1c30844d2dfe ("mm: reclaim small amounts of memory when an external fragmentation event occurs") "broke" memory management on parisc. The machine is not NUMA but the DISCONTIG model creates three pgdats even though it's a UMA machine for the following ranges 0) Start 0x0000000000000000 End 0x000000003fffffff Size 1024 MB 1) Start 0x0000000100000000 End 0x00000001bfdfffff Size 3070 MB 2) Start 0x0000004040000000 End 0x00000040ffffffff Size 3072 MB Mikulas reported: With the patch 1c30844d2, the kernel will incorrectly reclaim the first zone when it fills up, ignoring the fact that there are two completely free zones. Basiscally, it limits cache size to 1GiB. For example, if I run: # dd if=/dev/sda of=/dev/null bs=1M count=2048 - with the proper kernel, there should be "Buffers - 2GiB" when this command finishes. With the patch 1c30844d2, buffers will consume just 1GiB or slightly more, because the kernel was incorrectly reclaiming them. The page allocator and reclaim makes assumptions that pgdats really represent NUMA nodes and zones represent ranges and makes decisions on that basis. Watermark boosting for small pgdats leads to unexpected results even though this would have behaved reasonably on SPARSEMEM. DISCONTIG is essentially deprecated and even parisc plans to move to SPARSEMEM so there is no need to be fancy, this patch simply disables watermark boosting by default on DISCONTIGMEM. Link: http://lkml.kernel.org/r/20190419094335.GJ18914@techsingularity.net Fixes: 1c30844d2dfe ("mm: reclaim small amounts of memory when an external fragmentation event occurs") Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Mikulas Patocka <mpatocka@redhat.com> Tested-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: James Bottomley <James.Bottomley@hansenpartnership.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-26lib/test_vmalloc.c: do not create cpumask_t variable on stackUladzislau Rezki (Sony)1-3/+3
On my "Intel(R) Xeon(R) W-2135 CPU @ 3.70GHz" system(12 CPUs) i get the warning from the compiler about frame size: warning: the frame size of 1096 bytes is larger than 1024 bytes [-Wframe-larger-than=] the size of cpumask_t depends on number of CPUs, therefore just make use of cpumask_of() in set_cpus_allowed_ptr() as a second argument. Link: http://lkml.kernel.org/r/20190418193925.9361-1-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Roman Gushchin <guro@fb.com> Cc: Uladzislau Rezki <urezki@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Thomas Garnier <thgarnie@google.com> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Joel Fernandes <joelaf@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-26lib/Kconfig.debug: fix build error without CONFIG_BLOCKYueHaibing1-0/+1
If CONFIG_TEST_KMOD is set to M, while CONFIG_BLOCK is not set, XFS and BTRFS can not be compiled successly. Link: http://lkml.kernel.org/r/20190410075434.35220-1-yuehaibing@huawei.com Fixes: d9c6a72d6fa2 ("kmod: add test driver to stress test the module loader") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reported-by: Hulk Robot <hulkci@huawei.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Joe Lawrence <joe.lawrence@redhat.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-26zram: pass down the bvec we need to read into in the work structJérôme Glisse1-2/+3
When scheduling work item to read page we need to pass down the proper bvec struct which points to the page to read into. Before this patch it uses a randomly initialized bvec (only if PAGE_SIZE != 4096) which is wrong. Note that without this patch on arch/kernel where PAGE_SIZE != 4096 userspace could read random memory through a zram block device (thought userspace probably would have no control on the address being read). Link: http://lkml.kernel.org/r/20190408183219.26377-1-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-26mm/memory_hotplug.c: drop memory device reference after find_memory_block()David Hildenbrand1-0/+1
Right now we are using find_memory_block() to get the node id for the pfn range to online. We are missing to drop a reference to the memory block device. While the device still gets unregistered via device_unregister(), resulting in no user visible problem, the device is never released via device_release(), resulting in a memory leak. Fix that by properly using a put_device(). Link: http://lkml.kernel.org/r/20190411110955.1430-1-david@redhat.com Fixes: d0dc12e86b31 ("mm/memory_hotplug: optimize memory hotplug") Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Pankaj Gupta <pagupta@redhat.com> Cc: David Hildenbrand <david@redhat.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Qian Cai <cai@lca.pw> Cc: Arun KS <arunks@codeaurora.org> Cc: Mathieu Malaterre <malat@debian.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-04-26trace: Fix preempt_enable_no_resched() abusePeter Zijlstra1-1/+1
Unless the very next line is schedule(), or implies it, one must not use preempt_enable_no_resched(). It can cause a preemption to go missing and thereby cause arbitrary delays, breaking the PREEMPT=y invariant. Link: http://lkml.kernel.org/r/20190423200318.GY14281@hirez.programming.kicks-ass.net Cc: Waiman Long <longman@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: the arch/x86 maintainers <x86@kernel.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: huang ying <huang.ying.caritas@gmail.com> Cc: Roman Gushchin <guro@fb.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: stable@vger.kernel.org Fixes: 2c2d7329d8af ("tracing/ftrace: use preempt_enable_no_resched_notrace in ring_buffer_time_stamp()") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-26tracing: Fix a memory leak by early error exit in trace_pid_write()Wenwen Wang1-1/+4
In trace_pid_write(), the buffer for trace parser is allocated through kmalloc() in trace_parser_get_init(). Later on, after the buffer is used, it is then freed through kfree() in trace_parser_put(). However, it is possible that trace_pid_write() is terminated due to unexpected errors, e.g., ENOMEM. In that case, the allocated buffer will not be freed, which is a memory leak bug. To fix this issue, free the allocated buffer when an error is encountered. Link: http://lkml.kernel.org/r/1555726979-15633-1-git-send-email-wang6495@umn.edu Fixes: f4d34a87e9c10 ("tracing: Use pid bitmap instead of a pid array for set_event_pid") Cc: stable@vger.kernel.org Signed-off-by: Wenwen Wang <wang6495@umn.edu> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-26tracing: Fix buffer_ref pipe opsJann Horn3-16/+17
This fixes multiple issues in buffer_pipe_buf_ops: - The ->steal() handler must not return zero unless the pipe buffer has the only reference to the page. But generic_pipe_buf_steal() assumes that every reference to the pipe is tracked by the page's refcount, which isn't true for these buffers - buffer_pipe_buf_get(), which duplicates a buffer, doesn't touch the page's refcount. Fix it by using generic_pipe_buf_nosteal(), which refuses every attempted theft. It should be easy to actually support ->steal, but the only current users of pipe_buf_steal() are the virtio console and FUSE, and they also only use it as an optimization. So it's probably not worth the effort. - The ->get() and ->release() handlers can be invoked concurrently on pipe buffers backed by the same struct buffer_ref. Make them safe against concurrency by using refcount_t. - The pointers stored in ->private were only zeroed out when the last reference to the buffer_ref was dropped. As far as I know, this shouldn't be necessary anyway, but if we do it, let's always do it. Link: http://lkml.kernel.org/r/20190404215925.253531-1-jannh@google.com Cc: Ingo Molnar <mingo@redhat.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: stable@vger.kernel.org Fixes: 73a757e63114d ("ring-buffer: Return reader page back into existing ring buffer") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-15 13:07:14 +0300