July 2025 - Linux-stable-mirror

[PATCH 5.10.y] comedi: Fail COMEDI_INSNLIST ioctl if n_insns is too large

by Ian Abbott

[ Upstream commit 08ae4b20f5e82101d77326ecab9089e110f224cc ] The handling of the `COMEDI_INSNLIST` ioctl allocates a kernel buffer to hold the array of `struct comedi_insn`, getting the length from the `n_insns` member of the `struct comedi_insnlist` supplied by the user. The allocation will fail with a WARNING and a stack dump if it is too large. Avoid that by failing with an `-EINVAL` error if the supplied `n_insns` value is unreasonable. Define the limit on the `n_insns` value in the `MAX_INSNS` macro. Set this to the same value as `MAX_SAMPLES` (65536), which is the maximum allowed sum of the values of the member `n` in the array of `struct comedi_insn`, and sensible comedi instructions will have an `n` of at least 1. Reported-by: syzbot+d6995b62e5ac7d79557a(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d6995b62e5ac7d79557a Fixes: ed9eccbe8970 ("Staging: add comedi core") Tested-by: Ian Abbott <abbotti(a)mev.co.uk> Cc: stable(a)vger.kernel.org # 5.13+ Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk> Link: https://lore.kernel.org/r/20250704120405.83028-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/staging/comedi/comedi_fops.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 8f896e6208a8..5aa6a84d1fa6 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1584,6 +1584,16 @@ static int do_insnlist_ioctl(struct comedi_device *dev, return i; } +#define MAX_INSNS MAX_SAMPLES +static int check_insnlist_len(struct comedi_device *dev, unsigned int n_insns) +{ + if (n_insns > MAX_INSNS) { + dev_dbg(dev->class_dev, "insnlist length too large\n"); + return -EINVAL; + } + return 0; +} + /* * COMEDI_INSN ioctl * synchronous instruction @@ -2234,6 +2244,9 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd, rc = -EFAULT; break; } + rc = check_insnlist_len(dev, insnlist.n_insns); + if (rc) + break; insns = kcalloc(insnlist.n_insns, sizeof(*insns), GFP_KERNEL); if (!insns) { rc = -ENOMEM; @@ -3085,6 +3098,9 @@ static int compat_insnlist(struct file *file, unsigned long arg) if (copy_from_user(&insnlist32, compat_ptr(arg), sizeof(insnlist32))) return -EFAULT; + rc = check_insnlist_len(dev, insnlist32.n_insns); + if (rc) + return rc; insns = kcalloc(insnlist32.n_insns, sizeof(*insns), GFP_KERNEL); if (!insns) return -ENOMEM; -- 2.47.2

2 months, 2 weeks

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[PATCH 5.10.y] comedi: pcl812: Fix bit shift out of bounds

by Ian Abbott

[ Upstream commit b14b076ce593f72585412fc7fd3747e03a5e3632 ] When checking for a supported IRQ number, the following test is used: if ((1 << it->options[1]) & board->irq_bits) { However, `it->options[i]` is an unchecked `int` value from userspace, so the shift amount could be negative or out of bounds. Fix the test by requiring `it->options[1]` to be within bounds before proceeding with the original test. Valid `it->options[1]` values that select the IRQ will be in the range [1,15]. The value 0 explicitly disables the use of interrupts. Reported-by: syzbot+32de323b0addb9e114ff(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=32de323b0addb9e114ff Fixes: fcdb427bc7cf ("Staging: comedi: add pcl821 driver") Cc: stable(a)vger.kernel.org # 5.13+ Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk> Link: https://lore.kernel.org/r/20250707133429.73202-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/staging/comedi/drivers/pcl812.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/staging/comedi/drivers/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c index b87ab3840eee..fc06f284ba74 100644 --- a/drivers/staging/comedi/drivers/pcl812.c +++ b/drivers/staging/comedi/drivers/pcl812.c @@ -1151,7 +1151,8 @@ static int pcl812_attach(struct comedi_device *dev, struct comedi_devconfig *it) if (!dev->pacer) return -ENOMEM; - if ((1 << it->options[1]) & board->irq_bits) { + if (it->options[1] > 0 && it->options[1] < 16 && + (1 << it->options[1]) & board->irq_bits) { ret = request_irq(it->options[1], pcl812_interrupt, 0, dev->board_name, dev); if (ret == 0) -- 2.47.2

2 months, 2 weeks

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[PATCH 6.1.y] KVM: arm64: silence -Wuninitialized-const-pointer warning

by Justin Stitt

A new warning in Clang 22 [1] complains that @clidr passed to get_clidr_el1() is an uninitialized const pointer. get_clidr_el1() doesn't really care since it casts away the const-ness anyways. Silence the warning by initializing the struct. This patch won't apply to anything past v6.1 as this code section was reworked in Commit 7af0c2534f4c ("KVM: arm64: Normalize cache configuration"). Cc: stable(a)vger.kernel.org Fixes: 7c8c5e6a9101e ("arm64: KVM: system register handling") Link: https://github.com/llvm/llvm-project/commit/00dacf8c22f065cb52efb14cd091d44… [1] Signed-off-by: Justin Stitt <justinstitt(a)google.com> --- arch/arm64/kvm/sys_regs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index f4a7c5abcbca..d7ebd7387221 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -2948,7 +2948,7 @@ int kvm_sys_reg_table_init(void) { bool valid = true; unsigned int i; - struct sys_reg_desc clidr; + struct sys_reg_desc clidr = {0}; /* Make sure tables are unique and in order. */ valid &= check_sysreg_table(sys_reg_descs, ARRAY_SIZE(sys_reg_descs), false); --- base-commit: 830b3c68c1fb1e9176028d02ef86f3cf76aa2476 change-id: 20250724-b4-clidr-unint-const-ptr-7edb960bc3bd Best regards, -- Justin Stitt <justinstitt(a)google.com>

2 months, 2 weeks

5
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[PATCH 5.4.y] comedi: Fix use of uninitialized data in insn_rw_emulate_bits()

by Ian Abbott

[ Upstream commit e9cb26291d009243a4478a7ffb37b3a9175bfce9 ] For Comedi `INSN_READ` and `INSN_WRITE` instructions on "digital" subdevices (subdevice types `COMEDI_SUBD_DI`, `COMEDI_SUBD_DO`, and `COMEDI_SUBD_DIO`), it is common for the subdevice driver not to have `insn_read` and `insn_write` handler functions, but to have an `insn_bits` handler function for handling Comedi `INSN_BITS` instructions. In that case, the subdevice's `insn_read` and/or `insn_write` function handler pointers are set to point to the `insn_rw_emulate_bits()` function by `__comedi_device_postconfig()`. For `INSN_WRITE`, `insn_rw_emulate_bits()` currently assumes that the supplied `data[0]` value is a valid copy from user memory. It will at least exist because `do_insnlist_ioctl()` and `do_insn_ioctl()` in "comedi_fops.c" ensure at lease `MIN_SAMPLES` (16) elements are allocated. However, if `insn->n` is 0 (which is allowable for `INSN_READ` and `INSN_WRITE` instructions, then `data[0]` may contain uninitialized data, and certainly contains invalid data, possibly from a different instruction in the array of instructions handled by `do_insnlist_ioctl()`. This will result in an incorrect value being written to the digital output channel (or to the digital input/output channel if configured as an output), and may be reflected in the internal saved state of the channel. Fix it by returning 0 early if `insn->n` is 0, before reaching the code that accesses `data[0]`. Previously, the function always returned 1 on success, but it is supposed to be the number of data samples actually read or written up to `insn->n`, which is 0 in this case. Reported-by: syzbot+cb96ec476fb4914445c9(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=cb96ec476fb4914445c9 Fixes: ed9eccbe8970 ("Staging: add comedi core") Cc: stable(a)vger.kernel.org # 5.13+ Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk> Link: https://lore.kernel.org/r/20250707153355.82474-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/staging/comedi/drivers.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c index 6bb7b8a1e75d..ced660663f0d 100644 --- a/drivers/staging/comedi/drivers.c +++ b/drivers/staging/comedi/drivers.c @@ -615,6 +615,9 @@ static int insn_rw_emulate_bits(struct comedi_device *dev, unsigned int _data[2]; int ret; + if (insn->n == 0) + return 0; + memset(_data, 0, sizeof(_data)); memset(&_insn, 0, sizeof(_insn)); _insn.insn = INSN_BITS; -- 2.47.2

2 months, 2 weeks

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[PATCH 5.4.y] comedi: comedi_test: Fix possible deletion of uninitialized timers

by Ian Abbott

[ Upstream commit 1b98304c09a0192598d0767f1eb8c83d7e793091 ] In `waveform_common_attach()`, the two timers `&devpriv->ai_timer` and `&devpriv->ao_timer` are initialized after the allocation of the device private data by `comedi_alloc_devpriv()` and the subdevices by `comedi_alloc_subdevices()`. The function may return with an error between those function calls. In that case, `waveform_detach()` will be called by the Comedi core to clean up. The check that `waveform_detach()` uses to decide whether to delete the timers is incorrect. It only checks that the device private data was allocated, but that does not guarantee that the timers were initialized. It also needs to check that the subdevices were allocated. Fix it. Fixes: 73e0e4dfed4c ("staging: comedi: comedi_test: fix timer lock-up") Cc: stable(a)vger.kernel.org # 6.15+ Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk> Link: https://lore.kernel.org/r/20250708130627.21743-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> [ changed timer_delete_sync() to del_timer_sync() ] Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk> --- drivers/staging/comedi/drivers/comedi_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/staging/comedi/drivers/comedi_test.c b/drivers/staging/comedi/drivers/comedi_test.c index 9e60d2a0edc1..7397495de4d6 100644 --- a/drivers/staging/comedi/drivers/comedi_test.c +++ b/drivers/staging/comedi/drivers/comedi_test.c @@ -790,7 +790,7 @@ static void waveform_detach(struct comedi_device *dev) { struct waveform_private *devpriv = dev->private; - if (devpriv) { + if (devpriv && dev->n_subdevices) { del_timer_sync(&devpriv->ai_timer); del_timer_sync(&devpriv->ao_timer); } -- 2.47.2

2 months, 2 weeks

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[PATCH 6.6.y v2 1/1] 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> --- Changelog v1..v2: * Updated subject line 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

2 months, 2 weeks

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[PATCH 5.4.y] comedi: aio_iiro_16: Fix bit shift out of bounds

by Ian Abbott

When checking for a supported IRQ number, the following test is used: if ((1 << it->options[1]) & 0xdcfc) { However, `it->options[i]` is an unchecked `int` value from userspace, so the shift amount could be negative or out of bounds. Fix the test by requiring `it->options[1]` to be within bounds before proceeding with the original test. Valid `it->options[1]` values that select the IRQ will be in the range [1,15]. The value 0 explicitly disables the use of interrupts. Fixes: ad7a370c8be4 ("staging: comedi: aio_iiro_16: add command support for change of state detection") Cc: stable(a)vger.kernel.org # 5.13+ Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk> Link: https://lore.kernel.org/r/20250707134622.75403-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/staging/comedi/drivers/aio_iiro_16.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/staging/comedi/drivers/aio_iiro_16.c b/drivers/staging/comedi/drivers/aio_iiro_16.c index 41c9c56816ef..68be0ab0b80b 100644 --- a/drivers/staging/comedi/drivers/aio_iiro_16.c +++ b/drivers/staging/comedi/drivers/aio_iiro_16.c @@ -178,7 +178,8 @@ static int aio_iiro_16_attach(struct comedi_device *dev, * Digital input change of state interrupts are optionally supported * using IRQ 2-7, 10-12, 14, or 15. */ - if ((1 << it->options[1]) & 0xdcfc) { + if (it->options[1] > 0 && it->options[1] < 16 && + (1 << it->options[1]) & 0xdcfc) { ret = request_irq(it->options[1], aio_iiro_16_cos, 0, dev->board_name, dev); if (ret == 0) -- 2.47.2

2 months, 2 weeks

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[PATCH 5.10.y] comedi: Fix use of uninitialized data in insn_rw_emulate_bits()

by Ian Abbott

[ Upstream commit e9cb26291d009243a4478a7ffb37b3a9175bfce9 ] For Comedi `INSN_READ` and `INSN_WRITE` instructions on "digital" subdevices (subdevice types `COMEDI_SUBD_DI`, `COMEDI_SUBD_DO`, and `COMEDI_SUBD_DIO`), it is common for the subdevice driver not to have `insn_read` and `insn_write` handler functions, but to have an `insn_bits` handler function for handling Comedi `INSN_BITS` instructions. In that case, the subdevice's `insn_read` and/or `insn_write` function handler pointers are set to point to the `insn_rw_emulate_bits()` function by `__comedi_device_postconfig()`. For `INSN_WRITE`, `insn_rw_emulate_bits()` currently assumes that the supplied `data[0]` value is a valid copy from user memory. It will at least exist because `do_insnlist_ioctl()` and `do_insn_ioctl()` in "comedi_fops.c" ensure at lease `MIN_SAMPLES` (16) elements are allocated. However, if `insn->n` is 0 (which is allowable for `INSN_READ` and `INSN_WRITE` instructions, then `data[0]` may contain uninitialized data, and certainly contains invalid data, possibly from a different instruction in the array of instructions handled by `do_insnlist_ioctl()`. This will result in an incorrect value being written to the digital output channel (or to the digital input/output channel if configured as an output), and may be reflected in the internal saved state of the channel. Fix it by returning 0 early if `insn->n` is 0, before reaching the code that accesses `data[0]`. Previously, the function always returned 1 on success, but it is supposed to be the number of data samples actually read or written up to `insn->n`, which is 0 in this case. Reported-by: syzbot+cb96ec476fb4914445c9(a)syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=cb96ec476fb4914445c9 Fixes: ed9eccbe8970 ("Staging: add comedi core") Cc: stable(a)vger.kernel.org # 5.13+ Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk> Link: https://lore.kernel.org/r/20250707153355.82474-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/staging/comedi/drivers.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c index 6bb7b8a1e75d..ced660663f0d 100644 --- a/drivers/staging/comedi/drivers.c +++ b/drivers/staging/comedi/drivers.c @@ -615,6 +615,9 @@ static int insn_rw_emulate_bits(struct comedi_device *dev, unsigned int _data[2]; int ret; + if (insn->n == 0) + return 0; + memset(_data, 0, sizeof(_data)); memset(&_insn, 0, sizeof(_insn)); _insn.insn = INSN_BITS; -- 2.47.2

2 months, 2 weeks

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[PATCH 5.10.y] comedi: aio_iiro_16: Fix bit shift out of bounds

by Ian Abbott

When checking for a supported IRQ number, the following test is used: if ((1 << it->options[1]) & 0xdcfc) { However, `it->options[i]` is an unchecked `int` value from userspace, so the shift amount could be negative or out of bounds. Fix the test by requiring `it->options[1]` to be within bounds before proceeding with the original test. Valid `it->options[1]` values that select the IRQ will be in the range [1,15]. The value 0 explicitly disables the use of interrupts. Fixes: ad7a370c8be4 ("staging: comedi: aio_iiro_16: add command support for change of state detection") Cc: stable(a)vger.kernel.org # 5.13+ Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk> Link: https://lore.kernel.org/r/20250707134622.75403-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/staging/comedi/drivers/aio_iiro_16.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/staging/comedi/drivers/aio_iiro_16.c b/drivers/staging/comedi/drivers/aio_iiro_16.c index fe3876235075..60c9c683906b 100644 --- a/drivers/staging/comedi/drivers/aio_iiro_16.c +++ b/drivers/staging/comedi/drivers/aio_iiro_16.c @@ -178,7 +178,8 @@ static int aio_iiro_16_attach(struct comedi_device *dev, * Digital input change of state interrupts are optionally supported * using IRQ 2-7, 10-12, 14, or 15. */ - if ((1 << it->options[1]) & 0xdcfc) { + if (it->options[1] > 0 && it->options[1] < 16 && + (1 << it->options[1]) & 0xdcfc) { ret = request_irq(it->options[1], aio_iiro_16_cos, 0, dev->board_name, dev); if (ret == 0) -- 2.47.2

2 months, 2 weeks

2
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[PATCH 5.4.y] comedi: das6402: Fix bit shift out of bounds

by Ian Abbott

[ Upstream commit 70f2b28b5243df557f51c054c20058ae207baaac ] When checking for a supported IRQ number, the following test is used: /* IRQs 2,3,5,6,7, 10,11,15 are valid for "enhanced" mode */ if ((1 << it->options[1]) & 0x8cec) { However, `it->options[i]` is an unchecked `int` value from userspace, so the shift amount could be negative or out of bounds. Fix the test by requiring `it->options[1]` to be within bounds before proceeding with the original test. Valid `it->options[1]` values that select the IRQ will be in the range [1,15]. The value 0 explicitly disables the use of interrupts. Fixes: 79e5e6addbb1 ("staging: comedi: das6402: rewrite broken driver") Cc: stable(a)vger.kernel.org # 5.13+ Signed-off-by: Ian Abbott <abbotti(a)mev.co.uk> Link: https://lore.kernel.org/r/20250707135737.77448-1-abbotti@mev.co.uk Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> --- drivers/staging/comedi/drivers/das6402.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/staging/comedi/drivers/das6402.c b/drivers/staging/comedi/drivers/das6402.c index 0034005bdf8f..0cd5d1b1ffde 100644 --- a/drivers/staging/comedi/drivers/das6402.c +++ b/drivers/staging/comedi/drivers/das6402.c @@ -569,7 +569,8 @@ static int das6402_attach(struct comedi_device *dev, das6402_reset(dev); /* IRQs 2,3,5,6,7, 10,11,15 are valid for "enhanced" mode */ - if ((1 << it->options[1]) & 0x8cec) { + if (it->options[1] > 0 && it->options[1] < 16 && + (1 << it->options[1]) & 0x8cec) { ret = request_irq(it->options[1], das6402_interrupt, 0, dev->board_name, dev); if (ret == 0) { -- 2.47.2

2 months, 2 weeks

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Linux-stable-mirror July 2025