#ifndef INCLUDE_XEN_OPS_H #define INCLUDE_XEN_OPS_H #include #include #include #include #include DECLARE_PER_CPU(struct vcpu_info *, xen_vcpu); DECLARE_PER_CPU(uint32_t, xen_vcpu_id); static inline uint32_t xen_vcpu_nr(int cpu) { return per_cpu(xen_vcpu_id, cpu); } void xen_arch_pre_suspend(void); void xen_arch_post_suspend(int suspend_cancelled); void xen_timer_resume(void); void xen_arch_resume(void); void xen_arch_suspend(void); void xen_resume_notifier_register(struct notifier_block *nb); void xen_resume_notifier_unregister(struct notifier_block *nb); bool xen_vcpu_stolen(int vcpu); void xen_setup_runstate_info(int cpu); void xen_time_setup_guest(void); void xen_get_runstate_snapshot(struct vcpu_runstate_info *res); u64 xen_steal_clock(int cpu); int xen_setup_shutdown_event(void); extern unsigned long *xen_contiguous_bitmap; int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order, unsigned int address_bits, dma_addr_t *dma_handle); void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order); struct vm_area_struct; /* * xen_remap_domain_gfn_array() - map an array of foreign frames * @vma: VMA to map the pages into * @addr: Address at which to map the pages * @gfn: Array of GFNs to map * @nr: Number entries in the GFN array * @err_ptr: Returns per-GFN error status. * @prot: page protection mask * @domid: Domain owning the pages * @pages: Array of pages if this domain has an auto-translated physmap * * @gfn and @err_ptr may point to the same buffer, the GFNs will be * overwritten by the error codes after they are mapped. * * Returns the number of successfully mapped frames, or a -ve error * code. */ int xen_remap_domain_gfn_array(struct vm_area_struct *vma, unsigned long addr, xen_pfn_t *gfn, int nr, int *err_ptr, pgprot_t prot, unsigned domid, struct page **pages); /* xen_remap_domain_gfn_range() - map a range of foreign frames * @vma: VMA to map the pages into * @addr: Address at which to map the pages * @gfn: First GFN to map. * @nr: Number frames to map * @prot: page protection mask * @domid: Domain owning the pages * @pages: Array of pages if this domain has an auto-translated physmap * * Returns the number of successfully mapped frames, or a -ve error * code. */ int xen_remap_domain_gfn_range(struct vm_area_struct *vma, unsigned long addr, xen_pfn_t gfn, int nr, pgprot_t prot, unsigned domid, struct page **pages); int xen_unmap_domain_gfn_range(struct vm_area_struct *vma, int numpgs, struct page **pages); int xen_xlate_remap_gfn_array(struct vm_area_struct *vma, unsigned long addr, xen_pfn_t *gfn, int nr, int *err_ptr, pgprot_t prot, unsigned domid, struct page **pages); int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma, int nr, struct page **pages); int xen_xlate_map_ballooned_pages(xen_pfn_t **pfns, void **vaddr, unsigned long nr_grant_frames); bool xen_running_on_version_or_later(unsigned int major, unsigned int minor); efi_status_t xen_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc); efi_status_t xen_efi_set_time(efi_time_t *tm); efi_status_t xen_efi_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending, efi_time_t *tm); efi_status_t xen_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm); efi_status_t xen_efi_get_variable(efi_char16_t *name, efi_guid_t *vendor, u32 *attr, unsigned long *data_size, void *data); efi_status_t xen_efi_get_next_variable(unsigned long *name_size, efi_char16_t *name, efi_guid_t *vendor); efi_status_t xen_efi_set_variable(efi_char16_t *name, efi_guid_t *vendor, u32 attr, unsigned long data_size, void *data); efi_status_t xen_efi_query_variable_info(u32 attr, u64 *storage_space, u64 *remaining_space, u64 *max_variable_size); efi_status_t xen_efi_get_next_high_mono_count(u32 *count); efi_status_t xen_efi_update_capsule(efi_capsule_header_t **capsules, unsigned long count, unsigned long sg_list); efi_status_t xen_efi_query_capsule_caps(efi_capsule_header_t **capsules, unsigned long count, u64 *max_size, int *reset_type); #ifdef CONFIG_PREEMPT static inline void xen_preemptible_hcall_begin(void) { } static inline void xen_preemptible_hcall_end(void) { } #else DECLARE_PER_CPU(bool, xen_in_preemptible_hcall); static inline void xen_preemptible_hcall_begin(void) { __this_cpu_write(xen_in_preemptible_hcall, true); } static inline void xen_preemptible_hcall_end(void) { __this_cpu_write(xen_in_preemptible_hcall, false); } #endif /* CONFIG_PREEMPT */ #endif /* INCLUDE_XEN_OPS_H */ ble summary='commit info' class='commit-info'> authorLuis R. Rodriguez <mcgrof@kernel.org>2017-01-25 10:31:52 -0800 committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-01-27 09:19:48 +0100 commit191e885a2e130e639bb0c8ee350d7047294f2ce6 (patch) tree9bf9f9b4971df55a46e0a6750d3f6cd37bf1d9f0 /tools/spi/Makefile parent49def1853334396f948dcb4cedb9347abb318df5 (diff)
firmware: fix NULL pointer dereference in __fw_load_abort()
Since commit 5d47ec02c37ea6 ("firmware: Correct handling of fw_state_wait() return value") fw_load_abort() could be called twice and lead us to a kernel crash. This happens only when the firmware fallback mechanism (regular or custom) is used. The fallback mechanism exposes a sysfs interface for userspace to upload a file and notify the kernel when the file is loaded and ready, or to cancel an upload by echo'ing -1 into on the loading file: echo -n "-1" > /sys/$DEVPATH/loading This will call fw_load_abort(). Some distributions actually have a udev rule in place to *always* immediately cancel all firmware fallback mechanism requests (Debian), they have: $ cat /lib/udev/rules.d/50-firmware.rules # stub for immediately telling the kernel that userspace firmware loading # failed; necessary to avoid long timeouts with CONFIG_FW_LOADER_USER_HELPER=y SUBSYSTEM=="firmware", ACTION=="add", ATTR{loading}="-1 Distributions with this udev rule would run into this crash only if the fallback mechanism is used. Since most distributions disable by default using the fallback mechanism (CONFIG_FW_LOADER_USER_HELPER_FALLBACK), this would typicaly mean only 2 drivers which *require* the fallback mechanism could typically incur a crash: drivers/firmware/dell_rbu.c and the drivers/leds/leds-lp55xx-common.c driver. Distributions enabling CONFIG_FW_LOADER_USER_HELPER_FALLBACK by default are obviously more exposed to this crash. The crash happens because after commit 5b029624948d ("firmware: do not use fw_lock for fw_state protection") and subsequent fix commit 5d47ec02c37ea6 ("firmware: Correct handling of fw_state_wait() return value") a race can happen between this cancelation and the firmware fw_state_wait_timeout() being woken up after a state change with which fw_load_abort() as that calls swake_up(). Upon error fw_state_wait_timeout() will also again call fw_load_abort() and trigger a null reference. At first glance we could just fix this with a !buf check on fw_load_abort() before accessing buf->fw_st, however there is a logical issue in having a state machine used for the fallback mechanism and preventing access from it once we abort as its inside the buf (buf->fw_st). The firmware_class.c code is setting the buf to NULL to annotate an abort has occurred. Replace this mechanism by simply using the state check instead. All the other code in place already uses similar checks for aborting as well so no further changes are needed. An oops can be reproduced with the new fw_fallback.sh fallback mechanism cancellation test. Either cancelling the fallback mechanism or the custom fallback mechanism triggers a crash. mcgrof@piggy ~/linux-next/tools/testing/selftests/firmware (git::20170111-fw-fixes)$ sudo ./fw_fallback.sh ./fw_fallback.sh: timeout works ./fw_fallback.sh: firmware comparison works ./fw_fallback.sh: fallback mechanism works [ this then sits here when it is trying the cancellation test ] Kernel log: test_firmware: loading 'nope-test-firmware.bin' misc test_firmware: Direct firmware load for nope-test-firmware.bin failed with error -2 misc test_firmware: Falling back to user helper BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 IP: _request_firmware+0xa27/0xad0 PGD 0 Oops: 0000 [#1] SMP Modules linked in: test_firmware(E) ... etc ... CPU: 1 PID: 1396 Comm: fw_fallback.sh Tainted: G W E 4.10.0-rc3-next-20170111+ #30 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.1-0-g8891697-prebuilt.qemu-project.org 04/01/2014 task: ffff9740b27f4340 task.stack: ffffbb15c0bc8000 RIP: 0010:_request_firmware+0xa27/0xad0 RSP: 0018:ffffbb15c0bcbd10 EFLAGS: 00010246 RAX: 00000000fffffffe RBX: ffff9740afe5aa80 RCX: 0000000000000000 RDX: ffff9740b27f4340 RSI: 0000000000000283 RDI: 0000000000000000 RBP: ffffbb15c0bcbd90 R08: ffffbb15c0bcbcd8 R09: 0000000000000000 R10: 0000000894a0d4b1 R11: 000000000000008c R12: ffffffffc0312480 R13: 0000000000000005 R14: ffff9740b1c32400 R15: 00000000000003e8 FS: 00007f8604422700(0000) GS:ffff9740bfc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000038 CR3: 000000012164c000 CR4: 00000000000006e0 Call Trace: request_firmware+0x37/0x50 trigger_request_store+0x79/0xd0 [test_firmware] dev_attr_store+0x18/0x30 sysfs_kf_write+0x37/0x40 kernfs_fop_write+0x110/0x1a0 __vfs_write+0x37/0x160 ? _cond_resched+0x1a/0x50 vfs_write+0xb5/0x1a0 SyS_write+0x55/0xc0 ? trace_do_page_fault+0x37/0xd0 entry_SYSCALL_64_fastpath+0x1e/0xad RIP: 0033:0x7f8603f49620 RSP: 002b:00007fff6287b788 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055c307b110a0 RCX: 00007f8603f49620 RDX: 0000000000000016 RSI: 000055c3084d8a90 RDI: 0000000000000001 RBP: 0000000000000016 R08: 000000000000c0ff R09: 000055c3084d6336 R10: 000055c307b108b0 R11: 0000000000000246 R12: 000055c307b13c80 R13: 000055c3084d6320 R14: 0000000000000000 R15: 00007fff6287b950 Code: 9f 64 84 e8 9c 61 fe ff b8 f4 ff ff ff e9 6b f9 ff ff 48 c7 c7 40 6b 8d 84 89 45 a8 e8 43 84 18 00 49 8b be 00 03 00 00 8b 45 a8 <83> 7f 38 02 74 08 e8 6e ec ff ff 8b 45 a8 49 c7 86 00 03 00 00 RIP: _request_firmware+0xa27/0xad0 RSP: ffffbb15c0bcbd10 CR2: 0000000000000038 ---[ end trace 6d94ac339c133e6f ]--- Fixes: 5d47ec02c37e ("firmware: Correct handling of fw_state_wait() return value") Reported-and-Tested-by: Jakub Kicinski <jakub.kicinski@netronome.com> Reported-and-Tested-by: Patrick Bruenn <p.bruenn@beckhoff.com> Reported-by: Chris Wilson <chris@chris-wilson.co.uk> CC: <stable@vger.kernel.org> [3.10+] Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/spi/Makefile')