July 2025 - Linux-stable-mirror

[PATCH v2 1/4] riscv: use lw when reading int cpu in new_vmalloc_check

by Radim Krčmář

REG_L is wrong, because thread_info.cpu is 32-bit, not xlen-bit wide. The struct currently has a hole after cpu, so little endian accesses seemed fine. Fixes: 503638e0babf ("riscv: Stop emitting preventive sfence.vma for new vmalloc mappings") Cc: <stable(a)vger.kernel.org> Reviewed-by: Alexandre Ghiti <alexghiti(a)rivosinc.com> Signed-off-by: Radim Krčmář <rkrcmar(a)ventanamicro.com> --- v2: split for stable [Alex] --- arch/riscv/kernel/entry.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 75656afa2d6b..4fdf187a62bf 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -46,7 +46,7 @@ * a0 = &new_vmalloc[BIT_WORD(cpu)] * a1 = BIT_MASK(cpu) */ - REG_L a2, TASK_TI_CPU(tp) + lw a2, TASK_TI_CPU(tp) /* * Compute the new_vmalloc element position: * (cpu / 64) * 8 = (cpu >> 6) << 3 -- 2.50.0

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[PATCH] ALSA: hda/realtek - Fix mute LED for HP Victus 16-r1xxx

by edip＠medip.dev

From: Edip Hazuri <edip(a)medip.dev> The mute led on this laptop is using ALC245 but requires a quirk to work This patch enables the existing quirk for the device. Tested on Victus 16-r1xxx Laptop. The LED behaviour works as intended. v2: - adapt the HD-audio code changes and rebase on for-next branch of tiwai/sound.git - link to v1: https://lore.kernel.org/linux-sound/20250724210756.61453-2-edip@medip.dev/ Cc: <stable(a)vger.kernel.org> Signed-off-by: Edip Hazuri <edip(a)medip.dev> --- sound/hda/codecs/realtek/alc269.c | 1 + 1 file changed, 1 insertion(+) diff --git a/sound/hda/codecs/realtek/alc269.c b/sound/hda/codecs/realtek/alc269.c index 05019fa73..33ef08d25 100644 --- a/sound/hda/codecs/realtek/alc269.c +++ b/sound/hda/codecs/realtek/alc269.c @@ -6580,6 +6580,7 @@ static const struct hda_quirk alc269_fixup_tbl[] = { SND_PCI_QUIRK(0x103c, 0x8c91, "HP EliteBook 660", ALC236_FIXUP_HP_GPIO_LED), SND_PCI_QUIRK(0x103c, 0x8c96, "HP", ALC236_FIXUP_HP_MUTE_LED_MICMUTE_VREF), SND_PCI_QUIRK(0x103c, 0x8c97, "HP ZBook", ALC236_FIXUP_HP_MUTE_LED_MICMUTE_VREF), + SND_PCI_QUIRK(0x103c, 0x8c99, "HP Victus 16-r1xxx (MB 8C99)", ALC245_FIXUP_HP_MUTE_LED_COEFBIT), SND_PCI_QUIRK(0x103c, 0x8c9c, "HP Victus 16-s1xxx (MB 8C9C)", ALC245_FIXUP_HP_MUTE_LED_COEFBIT), SND_PCI_QUIRK(0x103c, 0x8ca1, "HP ZBook Power", ALC236_FIXUP_HP_GPIO_LED), SND_PCI_QUIRK(0x103c, 0x8ca2, "HP ZBook Power", ALC236_FIXUP_HP_GPIO_LED), -- 2.50.1

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[PATCH] ALSA: hda/realtek - Fix mute LED for HP Victus 16-r1xxx

by edip＠medip.dev

From: Edip Hazuri <edip(a)medip.dev> The mute led on this laptop is using ALC245 but requires a quirk to work This patch enables the existing quirk for the device. Tested on Victus 16-r1xxx Laptop. The LED behaviour works as intended. Cc: <stable(a)vger.kernel.org> Signed-off-by: Edip Hazuri <edip(a)medip.dev> --- sound/pci/hda/patch_realtek.c | 1 + 1 file changed, 1 insertion(+) diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c index 2627e2f49..9656e6ebb 100644 --- a/sound/pci/hda/patch_realtek.c +++ b/sound/pci/hda/patch_realtek.c @@ -10874,6 +10874,7 @@ static const struct hda_quirk alc269_fixup_tbl[] = { SND_PCI_QUIRK(0x103c, 0x8c91, "HP EliteBook 660", ALC236_FIXUP_HP_GPIO_LED), SND_PCI_QUIRK(0x103c, 0x8c96, "HP", ALC236_FIXUP_HP_MUTE_LED_MICMUTE_VREF), SND_PCI_QUIRK(0x103c, 0x8c97, "HP ZBook", ALC236_FIXUP_HP_MUTE_LED_MICMUTE_VREF), + SND_PCI_QUIRK(0x103c, 0x8c99, "HP Victus 16-r1xxx (MB 8C99)", ALC245_FIXUP_HP_MUTE_LED_COEFBIT), SND_PCI_QUIRK(0x103c, 0x8c9c, "HP Victus 16-s1xxx (MB 8C9C)", ALC245_FIXUP_HP_MUTE_LED_COEFBIT), SND_PCI_QUIRK(0x103c, 0x8ca1, "HP ZBook Power", ALC236_FIXUP_HP_GPIO_LED), SND_PCI_QUIRK(0x103c, 0x8ca2, "HP ZBook Power", ALC236_FIXUP_HP_GPIO_LED), -- 2.50.1

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[PATCH] comedi: Make insn_rw_emulate_bits() do insn->n samples

by Ian Abbott

The `insn_rw_emulate_bits()` function is used as a default handler for `INSN_READ` instructions for subdevices that have a handler for `INSN_BITS` but not for `INSN_READ`. Similarly, it is used as a default handler for `INSN_WRITE` instructions for subdevices that have a handler for `INSN_BITS` but not for `INSN_WRITE`. It works by emulating the `INSN_READ` or `INSN_WRITE` instruction handling with a constructed `INSN_BITS` instruction. However, `INSN_READ` and `INSN_WRITE` instructions are supposed to be able read or write multiple samples, indicated by the `insn->n` value, but `insn_rw_emulate_bits()` currently only handles a single sample. For `INSN_READ`, the comedi core will copy `insn->n` samples back to user-space. (That triggered KASAN kernel-infoleak errors when `insn->n` was greater than 1, but that is being fixed more generally elsewhere in the comedi core.) Make `insn_rw_emulate_bits()` either handle `insn->n` samples, or return an error, to conform to the general expectation for `INSN_READ` and `INSN_WRITE` handlers. Fixes: ed9eccbe8970 ("Staging: add comedi core") Cc: <stable(a)vger.kernel.org> # 5.13+ Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk> --- For 5.4.y and 5.10.y, this patch conflicts with submitted patches for upstream commit e9cb26291d00 ("comedi: Fix use of uninitialized data in insn_rw_emulate_bits()"). --- drivers/comedi/drivers.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/drivers/comedi/drivers.c b/drivers/comedi/drivers.c index f1dc854928c1..c9ebaadc5e82 100644 --- a/drivers/comedi/drivers.c +++ b/drivers/comedi/drivers.c @@ -620,11 +620,9 @@ static int insn_rw_emulate_bits(struct comedi_device *dev, unsigned int chan = CR_CHAN(insn->chanspec); unsigned int base_chan = (chan < 32) ? 0 : chan; unsigned int _data[2]; + unsigned int i; int ret; - if (insn->n == 0) - return 0; - memset(_data, 0, sizeof(_data)); memset(&_insn, 0, sizeof(_insn)); _insn.insn = INSN_BITS; @@ -635,18 +633,21 @@ static int insn_rw_emulate_bits(struct comedi_device *dev, if (insn->insn == INSN_WRITE) { if (!(s->subdev_flags & SDF_WRITABLE)) return -EINVAL; - _data[0] = 1U << (chan - base_chan); /* mask */ - _data[1] = data[0] ? (1U << (chan - base_chan)) : 0; /* bits */ + _data[0] = 1U << (chan - base_chan); /* mask */ } + for (i = 0; i < insn->n; i++) { + if (insn->insn == INSN_WRITE) + _data[1] = data[i] ? _data[0] : 0; /* bits */ - ret = s->insn_bits(dev, s, &_insn, _data); - if (ret < 0) - return ret; + ret = s->insn_bits(dev, s, &_insn, _data); + if (ret < 0) + return ret; - if (insn->insn == INSN_READ) - data[0] = (_data[1] >> (chan - base_chan)) & 1; + if (insn->insn == INSN_READ) + data[i] = (_data[1] >> (chan - base_chan)) & 1; + } - return 1; + return insn->n; } static int __comedi_device_postconfig_async(struct comedi_device *dev, -- 2.47.2

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[PATCH] scsi: fill in DMA padding bytes in scsi_alloc_sgtables

by Petr Vaganov

During fuzz testing, the following issue was discovered: BUG: KMSAN: uninit-value in __dma_map_sg_attrs+0x217/0x310 __dma_map_sg_attrs+0x217/0x310 dma_map_sg_attrs+0x4a/0x70 ata_qc_issue+0x9f8/0x1420 __ata_scsi_queuecmd+0x1657/0x1740 ata_scsi_queuecmd+0x79a/0x920 scsi_queue_rq+0x4472/0x4f40 blk_mq_dispatch_rq_list+0x1cca/0x3ee0 __blk_mq_sched_dispatch_requests+0x458/0x630 blk_mq_sched_dispatch_requests+0x15b/0x340 __blk_mq_run_hw_queue+0xe5/0x250 __blk_mq_delay_run_hw_queue+0x138/0x780 blk_mq_run_hw_queue+0x4bb/0x7e0 blk_mq_sched_insert_request+0x2a7/0x4c0 blk_execute_rq+0x497/0x8a0 sg_io+0xbe0/0xe20 scsi_ioctl+0x2b36/0x3c60 sr_block_ioctl+0x319/0x440 blkdev_ioctl+0x80f/0xd70 __se_sys_ioctl+0x219/0x420 __x64_sys_ioctl+0x93/0xe0 x64_sys_call+0x1d6c/0x3ad0 do_syscall_64+0x4c/0xa0 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Uninit was created at: __alloc_pages+0x5c0/0xc80 alloc_pages+0xe0e/0x1050 blk_rq_map_user_iov+0x2b77/0x6100 blk_rq_map_user_io+0x2fa/0x4d0 sg_io+0xad6/0xe20 scsi_ioctl+0x2b36/0x3c60 sr_block_ioctl+0x319/0x440 blkdev_ioctl+0x80f/0xd70 __se_sys_ioctl+0x219/0x420 __x64_sys_ioctl+0x93/0xe0 x64_sys_call+0x1d6c/0x3ad0 do_syscall_64+0x4c/0xa0 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 Bytes 14-15 of 16 are uninitialized Memory access of size 16 starts at ffff88800cbdb000 When processing the last unaligned element of the scatterlist, it is supplemented with missing bytes in the amount of pad_len. These bytes remain uninitialized, which leads to a problem. Add zeroing pad_len bytes of padding by pad_offset offset before increasing its length. This ensures that the DMA does not receive uninitialized data and eliminates the KMSAN warning. In this case, the pages are not located in highmem, but in the general case they might be, so kmap_local_page() is used for mapping. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: 40b01b9bbdf5 ("block: update bio according to DMA alignment padding") Co-developed-by: Boris Tonofa <b.tonofa(a)ideco.ru> Signed-off-by: Boris Tonofa <b.tonofa(a)ideco.ru> Signed-off-by: Petr Vaganov <p.vaganov(a)ideco.ru> --- drivers/scsi/scsi_lib.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 144c72f0737a..d287e24b6013 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1153,6 +1153,11 @@ blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd) if (blk_rq_bytes(rq) & rq->q->limits.dma_pad_mask) { unsigned int pad_len = (rq->q->limits.dma_pad_mask & ~blk_rq_bytes(rq)) + 1; + unsigned int pad_offset = last_sg->offset + last_sg->length; + void *vaddr = kmap_local_page(sg_page(last_sg)); + + memset(vaddr + pad_offset, 0, pad_len); + kunmap_local(vaddr); last_sg->length += pad_len; cmd->extra_len += pad_len; -- 2.50.1

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[PATCH v5] riscv: hwprobe: Fix stale vDSO data for late-initialized keys at boot

by Jingwei Wang

The hwprobe vDSO data for some keys, like MISALIGNED_VECTOR_PERF, is determined by an asynchronous kthread. This can create a race condition where the kthread finishes after the vDSO data has already been populated, causing userspace to read stale values. To fix this, a completion-based framework is introduced to robustly synchronize the async probes with the vDSO data population. The waiting function, init_hwprobe_vdso_data(), now blocks on wait_for_completion() until all probes signal they are done. Furthermore, to prevent this potential blocking from impacting boot performance, the initialization is deferred to late_initcall. This is safe as the data is only required by userspace (which starts much later) and moves the synchronization delay off the critical boot path. Reported-by: Tsukasa OI <research_trasio(a)irq.a4lg.com> Closes: https://lore.kernel.org/linux-riscv/760d637b-b13b-4518-b6bf-883d55d44e7f@ir… Fixes: e7c9d66e313b ("RISC-V: Report vector unaligned access speed hwprobe") Cc: Palmer Dabbelt <palmer(a)dabbelt.com> Cc: Alexandre Ghiti <alexghiti(a)rivosinc.com> Cc: Olof Johansson <olof(a)lixom.net> Cc: stable(a)vger.kernel.org Signed-off-by: Jingwei Wang <wangjingwei(a)iscas.ac.cn> --- Changes in v5: - Reworked the synchronization logic to a robust "sentinel-count" pattern based on feedback from Alexandre. - Fixed a "multiple definition" linker error for nommu builds by changing the header-file stub functions to `static inline`, as pointed out by Olof. - Updated the commit message to better explain the rationale for moving the vDSO initialization to `late_initcall`. Changes in v4: - Reworked the synchronization mechanism based on feedback from Palmer and Alexandre. - Instead of a post-hoc refresh, this version introduces a robust completion-based framework using an atomic counter to ensure async probes are finished before populating the vDSO. - Moved the vdso data initialization to a late_initcall to avoid impacting boot time. Changes in v3: - Retained existing blank line. Changes in v2: - Addressed feedback from Yixun's regarding #ifdef CONFIG_MMU usage. - Updated commit message to provide a high-level summary. - Added Fixes tag for commit e7c9d66e313b. v1: https://lore.kernel.org/linux-riscv/20250521052754.185231-1-wangjingwei@isc… arch/riscv/include/asm/hwprobe.h | 8 +++++++- arch/riscv/kernel/sys_hwprobe.c | 20 +++++++++++++++++++- arch/riscv/kernel/unaligned_access_speed.c | 9 +++++++-- 3 files changed, 33 insertions(+), 4 deletions(-) diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h index 7fe0a379474ae2c6..3b2888126e659ea1 100644 --- a/arch/riscv/include/asm/hwprobe.h +++ b/arch/riscv/include/asm/hwprobe.h @@ -40,5 +40,11 @@ static inline bool riscv_hwprobe_pair_cmp(struct riscv_hwprobe *pair, return pair->value == other_pair->value; } - +#ifdef CONFIG_MMU +void riscv_hwprobe_register_async_probe(void); +void riscv_hwprobe_complete_async_probe(void); +#else +static inline void riscv_hwprobe_register_async_probe(void) {} +static inline void riscv_hwprobe_complete_async_probe(void) {} +#endif #endif diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c index 0b170e18a2beba57..ee02aeb03e7bd3d8 100644 --- a/arch/riscv/kernel/sys_hwprobe.c +++ b/arch/riscv/kernel/sys_hwprobe.c @@ -5,6 +5,8 @@ * more details. */ #include <linux/syscalls.h> +#include <linux/completion.h> +#include <linux/atomic.h> #include <asm/cacheflush.h> #include <asm/cpufeature.h> #include <asm/hwprobe.h> @@ -467,6 +469,20 @@ static int do_riscv_hwprobe(struct riscv_hwprobe __user *pairs, #ifdef CONFIG_MMU +static DECLARE_COMPLETION(boot_probes_done); +static atomic_t pending_boot_probes = ATOMIC_INIT(1); + +void riscv_hwprobe_register_async_probe(void) +{ + atomic_inc(&pending_boot_probes); +} + +void riscv_hwprobe_complete_async_probe(void) +{ + if (atomic_dec_and_test(&pending_boot_probes)) + complete(&boot_probes_done); +} + static int __init init_hwprobe_vdso_data(void) { struct vdso_arch_data *avd = vdso_k_arch_data; @@ -474,6 +490,8 @@ static int __init init_hwprobe_vdso_data(void) struct riscv_hwprobe pair; int key; + if (unlikely(!atomic_dec_and_test(&pending_boot_probes))) + wait_for_completion(&boot_probes_done); /* * Initialize vDSO data with the answers for the "all CPUs" case, to * save a syscall in the common case. @@ -504,7 +522,7 @@ static int __init init_hwprobe_vdso_data(void) return 0; } -arch_initcall_sync(init_hwprobe_vdso_data); +late_initcall(init_hwprobe_vdso_data); #endif /* CONFIG_MMU */ diff --git a/arch/riscv/kernel/unaligned_access_speed.c b/arch/riscv/kernel/unaligned_access_speed.c index ae2068425fbcd207..4b8ad2673b0f7470 100644 --- a/arch/riscv/kernel/unaligned_access_speed.c +++ b/arch/riscv/kernel/unaligned_access_speed.c @@ -379,6 +379,7 @@ static void check_vector_unaligned_access(struct work_struct *work __always_unus static int __init vec_check_unaligned_access_speed_all_cpus(void *unused __always_unused) { schedule_on_each_cpu(check_vector_unaligned_access); + riscv_hwprobe_complete_async_probe(); return 0; } @@ -473,8 +474,12 @@ static int __init check_unaligned_access_all_cpus(void) per_cpu(vector_misaligned_access, cpu) = unaligned_vector_speed_param; } else if (!check_vector_unaligned_access_emulated_all_cpus() && IS_ENABLED(CONFIG_RISCV_PROBE_VECTOR_UNALIGNED_ACCESS)) { - kthread_run(vec_check_unaligned_access_speed_all_cpus, - NULL, "vec_check_unaligned_access_speed_all_cpus"); + riscv_hwprobe_register_async_probe(); + if (IS_ERR(kthread_run(vec_check_unaligned_access_speed_all_cpus, + NULL, "vec_check_unaligned_access_speed_all_cpus"))) { + pr_warn("Failed to create vec_unalign_check kthread\n"); + riscv_hwprobe_complete_async_probe(); + } } /* -- 2.50.0

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[PATCH] comedi: Fix use of uninitialized memory in do_insn_ioctl() and do_insnlist_ioctl()

by Ian Abbott

syzbot reports a KMSAN kernel-infoleak in `do_insn_ioctl()`. A kernel buffer is allocated to hold `insn->n` samples (each of which is an `unsigned int`). For some instruction types, `insn->n` samples are copied back to user-space, unless an error code is being returned. The problem is that not all the instruction handlers that need to return data to userspace fill in the whole `insn->n` samples, so that there is an information leak. There is a similar syzbot report for `do_insnlist_ioctl()`, although it does not have a reproducer for it at the time of writing. One culprit is `insn_rw_emulate_bits()` which is used as the handler for `INSN_READ` or `INSN_WRITE` instructions for subdevices that do not have a specific handler for that instruction, but do have an `INSN_BITS` handler. For `INSN_READ` it only fills in at most 1 sample, so if `insn->n` is greater than 1, the remaining `insn->n - 1` samples copied to userspace will be uninitialized kernel data. Another culprit is `vm80xx_ai_insn_read()` in the "vm80xx" driver. It never returns an error, even if it fails to fill the buffer. Fix it in `do_insn_ioctl()` and `do_insnlist_ioctl()` by making sure that uninitialized parts of the allocated buffer are zeroed before handling each instruction. Thanks to Arnaud Lecomte for their fix to `do_insn_ioctl()`. That fix replaced the call to `kmalloc_array()` with `kcalloc()`, but it is not always necessary to clear the whole buffer. Fixes: ed9eccbe8970 ("Staging: add comedi core") Reported-by: syzbot+a5e45f768aab5892da5d(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=a5e45f768aab5892da5d Reported-by: syzbot+fb4362a104d45ab09cf9(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=fb4362a104d45ab09cf9 Cc: <stable(a)vger.kernel.org> #5.13+ Cc: Arnaud Lecomte <contact(a)arnaud-lcm.com> Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk> --- Cherry picks to fix this for 5.4.y and 5.10.y not yet available. --- drivers/comedi/comedi_fops.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/comedi/comedi_fops.c b/drivers/comedi/comedi_fops.c index 23b7178522ae..7e2f2b1a1c36 100644 --- a/drivers/comedi/comedi_fops.c +++ b/drivers/comedi/comedi_fops.c @@ -1587,6 +1587,9 @@ static int do_insnlist_ioctl(struct comedi_device *dev, memset(&data[n], 0, (MIN_SAMPLES - n) * sizeof(unsigned int)); } + } else { + memset(data, 0, max_t(unsigned int, n, MIN_SAMPLES) * + sizeof(unsigned int)); } ret = parse_insn(dev, insns + i, data, file); if (ret < 0) @@ -1670,6 +1673,8 @@ static int do_insn_ioctl(struct comedi_device *dev, memset(&data[insn->n], 0, (MIN_SAMPLES - insn->n) * sizeof(unsigned int)); } + } else { + memset(data, 0, n_data * sizeof(unsigned int)); } ret = parse_insn(dev, insn, data, file); if (ret < 0) -- 2.47.2

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[stable backport request] x86/ioremap: Use is_ioremap_addr() in iounmap() for 5.15.y

by Arin Sun

Dear Stable Kernel Team and Maintainers, I am writing to request a backport of the following commit from the mainline kernel to the 5.15.y stable branch: Commit: x86/ioremap: Use is_ioremap_addr() in iounmap() ID: 50c6dbdfd16e312382842198a7919341ad480e05 Author: Max Ramanouski Merged in: Linux 6.11-rc1 (approximately August 2024) This commit fixes a bug in the iounmap() function for x86 architectures in kernel versions 5.x. Specifically, the original code uses a check against high_memory: if ((void __force *)addr <= high_memory) return; This can lead to memory leaks on certain x86 servers where ioremap() returns addresses that are not guaranteed to be greater than high_memory, causing the function to return early without properly unmapping the memory. The fix replaces this with is_ioremap_addr(), making the check more reliable: if (WARN_ON_ONCE(!is_ioremap_addr((void __force *)addr))) return; I have checked the 5.15.y branch logs and did not find this backport. This issue affects production environments, particularly on customer machines where we cannot easily deploy custom kernels. Backporting this to 5.15.y (and possibly other LTS branches like 5.10.y if applicable) would help resolve the memory leak without requiring users to upgrade to 6.x series. Do you have plans to backport this commit? If not, could you please consider it for inclusion in the stable releases? Thank you for your time and efforts in maintaining the stable kernels. Best regards, xin.sun

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[PATCH 6.6.y] arm64/cpufeatures/kvm: Add ARMv8.9 FEAT_ECBHB bits in ID_AA64MMFR1 register

by Roy, Patrick

From: Nianyao Tang <tangnianyao(a)huawei.com> [ upstream commit e8cde32f111f7f5681a7bad3ec747e9e697569a9 ] Enable ECBHB bits in ID_AA64MMFR1 register as per ARM DDI 0487K.a specification. When guest OS read ID_AA64MMFR1_EL1, kvm emulate this reg using ftr_id_aa64mmfr1 and always return ID_AA64MMFR1_EL1.ECBHB=0 to guest. It results in guest syscall jump to tramp ventry, which is not needed in implementation with ID_AA64MMFR1_EL1.ECBHB=1. Let's make the guest syscall process the same as the host. This fixes performance regressions introduced by commit 4117975672c4 ("arm64: errata: Add newer ARM cores to the spectre_bhb_loop_affected() lists") for guests running on neoverse v2 hardware, which supports ECBHB. Signed-off-by: Nianyao Tang <tangnianyao(a)huawei.com> Link: https://lore.kernel.org/r/20240611122049.2758600-1-tangnianyao@huawei.com Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com> Signed-off-by: Patrick Roy <roypat(a)amazon.co.uk> --- arch/arm64/kernel/cpufeature.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index b6d381f743f3..2ce9ef9d924a 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -364,6 +364,7 @@ static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = { }; static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = { + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_ECBHB_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_TIDCP1_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_AFP_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_HCX_SHIFT, 4, 0), -- 2.50.1

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[PATCH] block: Fix bounce check logic in blk_queue_may_bounce()

by Hardeep Sharma

Buffer bouncing is needed only when memory exists above the lowmem region, i.e., when max_low_pfn < max_pfn. The previous check (max_low_pfn >= max_pfn) was inverted and prevented bouncing when it could actually be required. Note that bouncing depends on CONFIG_HIGHMEM, which is typically enabled on 32-bit ARM where not all memory is permanently mapped into the kernel’s lowmem region. Fixes: 9bb33f24abbd0 ("block: refactor the bounce buffering code") Cc: stable(a)vger.kernel.org Signed-off-by: Hardeep Sharma <quic_hardshar(a)quicinc.com> --- block/blk.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk.h b/block/blk.h index 67915b04b3c1..f8a1d64be5a2 100644 --- a/block/blk.h +++ b/block/blk.h @@ -383,7 +383,7 @@ static inline bool blk_queue_may_bounce(struct request_queue *q) { return IS_ENABLED(CONFIG_BOUNCE) && q->limits.bounce == BLK_BOUNCE_HIGH && - max_low_pfn >= max_pfn; + max_low_pfn < max_pfn; } static inline struct bio *blk_queue_bounce(struct bio *bio, -- 2.25.1

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