kernel/linux.git/arch/powerpc, branch v6.6.145

powerpc/spufs: fix out-of-bounds access in spufs_mem_mmap_access()

2026-07-24T14:03:45+00:00

commit 47b87f469a35b5ffc81c16eee6b13a9b6c8d55c6 upstream. spufs_mem_mmap_access() computes the local store offset as address - vma->vm_start, but bounds-checks it against vma->vm_end instead of the local store size. On 64-bit, offset is always well below vma->vm_end, so the clamp never fires and len stays unbounded against the LS_SIZE buffer returned by ctx->ops->get_ls(). Reject offsets at or beyond LS_SIZE and clamp len to the remaining space, mirroring the guard already used by spufs_mem_mmap_fault() and spufs_ps_fault(). Fixes: a352894d0705 ("spufs: use new vm_ops->access to allow local state access from gdb") Reported-by: Yuhao Jiang Cc: stable@vger.kernel.org Signed-off-by: Junrui Luo Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/SYBPR01MB7881EE775E8B51C09F5A29E7AF152@SYBPR01MB7881.ausprd01.prod.outlook.com Signed-off-by: Greg Kroah-Hartman

powerpc/pseries: fix memory leak on krealloc failure in papr_init

2026-07-24T14:03:45+00:00

commit bd83c98b988d2c560531084e296dbfb530aff829 upstream. When krealloc() fails, free the original esi_buf before returning to avoid a memory leak. Fixes: 3c14b73454cf ("powerpc/pseries: Interface to represent PAPR firmware attributes") Cc: stable@vger.kernel.org Signed-off-by: Thorsten Blum Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260614142356.658212-2-thorsten.blum@linux.dev Signed-off-by: Greg Kroah-Hartman

powerpc/kexec: fix double get_cpu() imbalance in kexec_prepare_cpus

2026-07-24T14:03:13+00:00

[ Upstream commit 5c86f1c1f972761a04bf22f4c0618d1aa714185b ] kexec_prepare_cpus_wait() calls get_cpu() internally to obtain the current CPU id. kexec_prepare_cpus() calls kexec_prepare_cpus_wait() twice -- once for KEXEC_STATE_IRQS_OFF and once for KEXEC_STATE_REAL_MODE -- but only issues a single put_cpu() at the end, leaving preempt_count elevated by one extra nesting level. In practice the imbalance does not trigger a 'scheduling while atomic' splat because the kexec path is a one-way trip: IRQs are already disabled, no schedule() occurs after the leak, and default_machine_kexec() overwrites preempt_count with HARDIRQ_OFFSET before jumping into kexec_sequence() which never returns. However the bookkeeping is still wrong. kexec_prepare_cpus() calls local_irq_disable()/hard_irq_disable() before invoking kexec_prepare_cpus_wait(), so the CPU is already pinned and the get_cpu()/put_cpu() preempt_disable() bracketing is unnecessary. Only the current CPU id is needed, so replace get_cpu() with raw_smp_processor_id() and drop the now-unneeded put_cpu(). Fixes: 1fc711f7ffb0 ("powerpc/kexec: Fix race in kexec shutdown") Signed-off-by: Aboorva Devarajan Reviewed-by: Shrikanth Hegde Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260605082912.305100-4-aboorvad@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/powernv: fix preempt count leak in pnv_kexec_wait_secondaries_down

2026-07-24T14:03:13+00:00

[ Upstream commit 0ecd26e93e698c8327521910fc6296f5b84a4b92 ] pnv_kexec_wait_secondaries_down() calls get_cpu() to obtain the current CPU id but never calls the matching put_cpu(), leaking one preempt_disable() nesting level on every invocation. In practice the imbalance does not trigger a visible splat because the kexec teardown path is a one-way trip: IRQs are already disabled, no schedule() occurs after the leak, and default_machine_kexec() overwrites preempt_count with HARDIRQ_OFFSET before jumping into kexec_sequence() which never returns. However the bookkeeping is still wrong. The function only needs the current CPU id, and this path runs with interrupts disabled and the CPU pinned, so the preempt_disable() side-effect of get_cpu() is unnecessary. Replace it with raw_smp_processor_id(). Fixes: 298b34d7d578 ("powerpc/powernv: Fix kexec races going back to OPAL") Signed-off-by: Aboorva Devarajan Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260605082912.305100-3-aboorvad@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/perf: fix preempt count underflow in fsl_emb_pmu_del

2026-07-24T14:03:13+00:00

[ Upstream commit 81e3a86030462824a67d697739cf3f387f4ba350 ] fsl_emb_pmu_del() unconditionally calls put_cpu_var(cpu_hw_events) at the 'out:' label, but only calls the matching get_cpu_var() after the 'i < 0' early-return check. When event->hw.idx is negative the function jumps to 'out:' without having taken get_cpu_var(), and the trailing put_cpu_var() then issues an unmatched preempt_enable(), underflowing preempt_count. On a CONFIG_PREEMPT=y kernel preempt_count would underflow and eventually present as a 'scheduling while atomic' BUG. Move put_cpu_var() to pair with get_cpu_var() so the percpu access is correctly bracketed and the 'out:' label only handles perf_pmu_enable. Fixes: a11106544f33 ("powerpc/perf: e500 support") Reviewed-by: Shrikanth Hegde Signed-off-by: Aboorva Devarajan Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260605082912.305100-2-aboorvad@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/time: Remove redundant preempt_disable|enable() calls from arch_irq_work_raise()

2026-06-01T15:43:13+00:00

[ Upstream commit 31467b23823ffec1f6fff407f8e3ca9af8b7491a ] A kernel panic is observed when handling machine check exceptions from real mode. BUG: Unable to handle kernel data access on read at 0xc00000006be21300 Oops: Kernel access of bad area, sig: 11 [#1] MSR: 8000000000001003 CR: 88222248 XER: 00000005 CFAR: c00000000003ffc4 DAR: c00000006be21300 DSISR: 40000000 IRQMASK: 0 NIP [c000000000029e40] arch_irq_work_raise+0x10/0x70 LR [c00000000003ffc8] machine_check_queue_event+0xa8/0x150 Call Trace: [c0000000179d3c70] [c00000000003ff64] machine_check_queue_event+0x44/0x150 [c0000000179d3d30] [c0000000000084e0] machine_check_early_common+0x1f0/0x2c0 The crash occurs because arch_irq_work_raise() calls preempt_disable() from machine check exception (MCE) handlers running in real mode. In this context, accessing the preempt_count can fault, leading to the panic. The preempt_disable()/preempt_enable() pair in arch_irq_work_raise() was originally added by commit 0fe1ac48bef0 ("powerpc/perf_event: Fix oops due to perf_event_do_pending call") to avoid races while raising irq work from exception context. Later, commit 471ba0e686cb ("irq_work: Do not raise an IPI when queueing work on the local CPU") added preemption protection in irq_work_queue() path, while commit 20b876918c06 ("irq_work: Use per cpu atomics instead of regular atomics") added equivalent protection in irq_work_queue_on() before reaching arch_irq_work_raise(): irq_work_queue() / irq_work_queue_on() -> preempt_disable() -> __irq_work_queue_local() -> irq_work_raise() -> arch_irq_work_raise() As a result, callers other than mce_irq_work_raise() already execute with preemption disabled, making the additional preempt_disable()/preempt_enable() pair in arch_irq_work_raise() redundant. The arch_irq_work_raise() function executes in NMI context when called from MCE handler. Hence we will not be preempted or scheduled out since we are in NMI context with MSR[EE]=0. Therefore, it is safe to remove the preempt_disable()/preempt_enable() calls from here. Remove it to avoid accessing preempt_count from real mode context. Fixes: cc15ff327569 ("powerpc/mce: Avoid using irq_work_queue() in realmode") Suggested-by: Mahesh Salgaonkar Acked-by: Shrikanth Hegde Reviewed-by: Ritesh Harjani (IBM) Signed-off-by: Sayali Patil [Maddy: Fixed the commit title] Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260513081413.222490-1-sayalip@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/warp: Fix error handling in pika_dtm_thread

2026-05-23T11:03:33+00:00

commit 108d7f951271cbd36ca36efc5e5d106966f5180c upstream. pika_dtm_thread() acquires client through of_find_i2c_device_by_node() but fails to release it in error handling path. This could result in a reference count leak, preventing proper cleanup and potentially leading to resource exhaustion. Add put_device() to release the reference in the error handling path. Found by code review. Cc: stable@vger.kernel.org Fixes: 3984114f0562 ("powerpc/warp: Platform fix for i2c change") Signed-off-by: Ma Ke Reviewed-by: Christophe Leroy Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20251116024411.21968-1-make24@iscas.ac.cn Signed-off-by: Greg Kroah-Hartman

powerpc/crash: fix backup region offset update to elfcorehdr

2026-05-23T11:03:07+00:00

[ Upstream commit 789335cacdf37da93bb7c70322dff8c7e82881df ] update_backup_region_phdr() in file_load_64.c iterates over all the program headers in the kdump kernel’s elfcorehdr and updates the p_offset of the program header whose physical address starts at 0. However, the loop logic is incorrect because the program header pointer is not updated during iteration. Since elfcorehdr typically contains PT_NOTE entries first, the PT_LOAD program header with physical address 0 is never reached. As a result, its p_offset is not updated to point to the backup region. Because of this behavior, the capture kernel exports the first 64 KB of the crashed kernel’s memory at offset 0, even though that memory actually lives in the backup region. When a crash happens, purgatory copies the first 64 KB of the crashed kernel’s memory into the backup region so the capture kernel can safely use it. This has not caused problems so far because the first 64 KB is usually identical in both the crashed and capture kernels. However, this is just an assumption and is not guaranteed to always hold true. Fix update_backup_region_phdr() to correctly update the p_offset of the program header with a starting physical address of 0 by correcting the logic used to iterate over the program headers. Fixes: cb350c1f1f86 ("powerpc/kexec_file: Prepare elfcore header for crashing kernel") Reviewed-by: Aditya Gupta Signed-off-by: Sourabh Jain Reviewed-by: Hari Bathini Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260312083051.1935737-2-sourabhjain@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/kdump: fix KASAN sanitization flag for core_$(BITS).o

2026-05-17T15:13:37+00:00

commit b3a97f9484080c6e71db9e803e3cc1bb372a9bc7 upstream. KASAN instrumentation is intended to be disabled for the kexec core code, but the existing Makefile entry misses the object suffix. As a result, the flag is not applied correctly to core_$(BITS).o. So when KASAN is enabled, kexec_copy_flush and copy_segments in kexec/core_64.c are instrumented, which can result in accesses to shadow memory via normal address translation paths. Since these run with the MMU disabled, such accesses may trigger page faults (bad_page_fault) that cannot be handled in the kdump path, ultimately causing a hang and preventing the kdump kernel from booting. The same is true for kexec as well, since the same functions are used there. Update the entry to include the “.o” suffix so that KASAN instrumentation is properly disabled for this object file. Fixes: 2ab2d5794f14 ("powerpc/kasan: Disable address sanitization in kexec paths") Reported-by: Venkat Rao Bagalkote Closes: https://lore.kernel.org/all/1dee8891-8bcc-46b4-93f3-fc3a774abd5b@linux.ibm.com/ Cc: stable@vger.kernel.org Reviewed-by: Ritesh Harjani (IBM) Tested-by: Venkat Rao Bagalkote Acked-by: Mahesh Salgaonkar Reviewed-by: Aboorva Devarajan Tested-by: Aboorva Devarajan Signed-off-by: Sourabh Jain Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260407124349.1698552-1-sourabhjain@linux.ibm.com Signed-off-by: Greg Kroah-Hartman

powerpc64/bpf: do not increment tailcall count when prog is NULL

2026-04-02T11:07:29+00:00

commit 521bd39d9d28ce54cbfec7f9b89c94ad4fdb8350 upstream. Do not increment tailcall count, if tailcall did not succeed due to missing BPF program. Fixes: ce0761419fae ("powerpc/bpf: Implement support for tail calls") Cc: stable@vger.kernel.org Tested-by: Venkat Rao Bagalkote Signed-off-by: Hari Bathini Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260303181031.390073-2-hbathini@linux.ibm.com [ Conflict due to missing feature commit 2ed2d8f6fb38 ("powerpc64/bpf: Support tailcalls with subprogs") resolved accordingly. ] Signed-off-by: Hari Bathini Signed-off-by: Greg Kroah-Hartman