From: Jarkko Sakkinen <jarkko@kernel.org>
To: Denis Aleksandrov <daleksan@redhat.com>
Cc: Nathan Chancellor <nathan@kernel.org>,
peterhuewe@gmx.de, jgg@ziepe.ca, linux-integrity@vger.kernel.org,
Jan Stancek <jstancek@redhat.com>,
Paul Menzel <pmenzel@molgen.mpg.de>
Subject: Re: [PATCH v5] tpm: Prevent local DOS via tpm/tpm0/ppi/*operations
Date: Wed, 24 Sep 2025 20:04:29 +0300 [thread overview]
Message-ID: <aNQknT3Uo7oRfgXl@kernel.org> (raw)
In-Reply-To: <CAG+gbFcAJ7ppMbcyHsRFj=ZMteNV7GoUh5qkb+7iG2n4D5ONGg@mail.gmail.com>
On Wed, Sep 24, 2025 at 03:34:33AM -0400, Denis Aleksandrov wrote:
> On Tue, Sep 23, 2025 at 11:37 PM Jarkko Sakkinen <jarkko@kernel.org> wrote:
> >
> > On Wed, Sep 24, 2025 at 06:31:37AM +0300, Jarkko Sakkinen wrote:
> > > On Wed, Sep 24, 2025 at 03:57:23AM +0300, Jarkko Sakkinen wrote:
> > > > On Tue, Sep 23, 2025 at 01:07:48PM -0700, Nathan Chancellor wrote:
> > > > > Hi Denis,
> > > > >
> > > > > On Mon, Sep 15, 2025 at 05:08:29PM -0400, Denis Aleksandrov wrote:
> > > > > > Reads on tpm/tpm0/ppi/*operations can become very long on
> > > > > > misconfigured systems. Reading the TPM is a blocking operation,
> > > > > > thus a user could effectively trigger a DOS.
> > > > > >
> > > > > > Resolve this by caching the results and avoiding the blocking
> > > > > > operations after the first read.
> > > > > >
> > > > > > Reported-by: Jan Stancek <jstancek@redhat.com>
> > > > > > Signed-off-by: Denis Aleksandrov <daleksan@redhat.com>
> > > > > > Suggested-by: Jarkko Sakkinen <jarkko@kernel.org>
> > > > > > Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
> > > > > > Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> > > > > > ---
> > > > > >
> > > > > > Changes in v5:
> > > > > > - Unlocks the tpm_ppi_lock if cache_ppi_operations() returns and
> > > > > > error.
> > > > > >
> > > > > > drivers/char/tpm/tpm_ppi.c | 89 ++++++++++++++++++++++++++++----------
> > > > > > 1 file changed, 66 insertions(+), 23 deletions(-)
> > > > > >
> > > > > > diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c
> > > > > > index d53fce1c9d6f..47655407fea5 100644
> > > > > > --- a/drivers/char/tpm/tpm_ppi.c
> > > > > > +++ b/drivers/char/tpm/tpm_ppi.c
> > > > > > @@ -33,6 +33,20 @@ static const guid_t tpm_ppi_guid =
> > > > > > GUID_INIT(0x3DDDFAA6, 0x361B, 0x4EB4,
> > > > > > 0xA4, 0x24, 0x8D, 0x10, 0x08, 0x9D, 0x16, 0x53);
> > > > > >
> > > > > > +static const char * const tpm_ppi_info[] = {
> > > > > > + "Not implemented",
> > > > > > + "BIOS only",
> > > > > > + "Blocked for OS by system firmware",
> > > > > > + "User required",
> > > > > > + "User not required",
> > > > > > +};
> > > > > > +
> > > > > > +/* A spinlock to protect access to the cache from concurrent reads */
> > > > > > +static DEFINE_SPINLOCK(tpm_ppi_lock);
> > > > > > +
> > > > > > +static u32 ppi_operations_cache[PPI_VS_REQ_END + 1];
> > > > > > +static bool ppi_cache_populated;
> > > > > > +
> > > > > > static bool tpm_ppi_req_has_parameter(u64 req)
> > > > > > {
> > > > > > return req == 23;
> > > > > > @@ -277,8 +291,7 @@ static ssize_t tpm_show_ppi_response(struct device *dev,
> > > > > > return status;
> > > > > > }
> > > > > >
> > > > > > -static ssize_t show_ppi_operations(acpi_handle dev_handle, char *buf, u32 start,
> > > > > > - u32 end)
> > > > > > +static ssize_t cache_ppi_operations(acpi_handle dev_handle, char *buf)
> > > > > > {
> > > > > > int i;
> > > > > > u32 ret;
> > > > > > @@ -286,34 +299,22 @@ static ssize_t show_ppi_operations(acpi_handle dev_handle, char *buf, u32 start,
> > > > > > union acpi_object *obj, tmp;
> > > > > > union acpi_object argv = ACPI_INIT_DSM_ARGV4(1, &tmp);
> > > > > >
> > > > > > - static char *info[] = {
> > > > > > - "Not implemented",
> > > > > > - "BIOS only",
> > > > > > - "Blocked for OS by BIOS",
> > > > > > - "User required",
> > > > > > - "User not required",
> > > > > > - };
> > > > > > -
> > > > > > if (!acpi_check_dsm(dev_handle, &tpm_ppi_guid, TPM_PPI_REVISION_ID_1,
> > > > > > 1 << TPM_PPI_FN_GETOPR))
> > > > > > return -EPERM;
> > > > > >
> > > > > > tmp.integer.type = ACPI_TYPE_INTEGER;
> > > > > > - for (i = start; i <= end; i++) {
> > > > > > + for (i = 0; i <= PPI_VS_REQ_END; i++) {
> > > > > > tmp.integer.value = i;
> > > > > > obj = tpm_eval_dsm(dev_handle, TPM_PPI_FN_GETOPR,
> > > > > > ACPI_TYPE_INTEGER, &argv,
> > > > > > TPM_PPI_REVISION_ID_1);
> > > > > > - if (!obj) {
> > > > > > + if (!obj)
> > > > > > return -ENOMEM;
> > > > > > - } else {
> > > > > > - ret = obj->integer.value;
> > > > > > - ACPI_FREE(obj);
> > > > > > - }
> > > > > >
> > > > > > - if (ret > 0 && ret < ARRAY_SIZE(info))
> > > > > > - len += sysfs_emit_at(buf, len, "%d %d: %s\n",
> > > > > > - i, ret, info[ret]);
> > > > > > + ret = obj->integer.value;
> > > > > > + ppi_operations_cache[i] = ret;
> > > > > > + ACPI_FREE(obj);
> > > > > > }
> > > > > >
> > > > > > return len;
> > > > > > @@ -324,9 +325,30 @@ static ssize_t tpm_show_ppi_tcg_operations(struct device *dev,
> > > > > > char *buf)
> > > > > > {
> > > > > > struct tpm_chip *chip = to_tpm_chip(dev);
> > > > > > + ssize_t len = 0;
> > > > > > + u32 ret;
> > > > > > + int i;
> > > > > > +
> > > > > > + spin_lock(&tpm_ppi_lock);
> > > > > > + if (!ppi_cache_populated) {
> > > > > > + len = cache_ppi_operations(chip->acpi_dev_handle, buf);
> > > > > > + if (len < 0) {
> > > > > > + spin_unlock(&tpm_ppi_lock);
> > > > > > + return len;
> > > > > > + }
> > > > > >
> > > > > > - return show_ppi_operations(chip->acpi_dev_handle, buf, 0,
> > > > > > - PPI_TPM_REQ_MAX);
> > > > > > + ppi_cache_populated = true;
> > > > > > + }
> > > > > > +
> > > > > > + for (i = 0; i <= PPI_TPM_REQ_MAX; i++) {
> > > > > > + ret = ppi_operations_cache[i];
> > > > > > + if (ret >= 0 && ret < ARRAY_SIZE(tpm_ppi_info))
> > > > > > + len += sysfs_emit_at(buf, len, "%d %d: %s\n",
> > > > > > + i, ret, tpm_ppi_info[ret]);
> > > > > > + }
> > > > > > + spin_unlock(&tpm_ppi_lock);
> > > > > > +
> > > > > > + return len;
> > > > > > }
> > > > > >
> > > > > > static ssize_t tpm_show_ppi_vs_operations(struct device *dev,
> > > > > > @@ -334,9 +356,30 @@ static ssize_t tpm_show_ppi_vs_operations(struct device *dev,
> > > > > > char *buf)
> > > > > > {
> > > > > > struct tpm_chip *chip = to_tpm_chip(dev);
> > > > > > + ssize_t len = 0;
> > > > > > + u32 ret;
> > > > > > + int i;
> > > > > >
> > > > > > - return show_ppi_operations(chip->acpi_dev_handle, buf, PPI_VS_REQ_START,
> > > > > > - PPI_VS_REQ_END);
> > > > > > + spin_lock(&tpm_ppi_lock);
> > > > > > + if (!ppi_cache_populated) {
> > > > > > + len = cache_ppi_operations(chip->acpi_dev_handle, buf);
> > > > > > + if (len < 0) {
> > > > > > + spin_unlock(&tpm_ppi_lock);
> > > > > > + return len;
> > > > > > + }
> > > > > > +
> > > > > > + ppi_cache_populated = true;
> > > > > > + }
> > > > > > +
> > > > > > + for (i = PPI_VS_REQ_START; i <= PPI_VS_REQ_END; i++) {
> > > > > > + ret = ppi_operations_cache[i];
> > > > > > + if (ret >= 0 && ret < ARRAY_SIZE(tpm_ppi_info))
> > > > > > + len += sysfs_emit_at(buf, len, "%d %d: %s\n",
> > > > > > + i, ret, tpm_ppi_info[ret]);
> > > > > > + }
> > > > > > + spin_unlock(&tpm_ppi_lock);
> > > > > > +
> > > > > > + return len;
> > > > > > }
> > > > > >
> > > > > > static DEVICE_ATTR(version, S_IRUGO, tpm_show_ppi_version, NULL);
> > > > > > --
> > > > > > 2.48.1
> > > > > >
> > > > >
> > > > > I am seeing a "scheduling while atomic" splat in -next when running
> > > > > LTP's read_all testcase against /proc and /sys that I bisected to this
> > > > > change (bisect log at the end of the message). It is still reproducible
> > > > > with the most recent sha in Jarkko's tree, c4a211c65878 ("tpm: Prevent
> > > > > local DOS via tpm/tpm0/ppi/*operations"), where there is no difference
> > > > > in the code as far as I can tell.
> > > > >
> > > > > $ curl -LSs https://github.com/nathanchance/env/raw/014a117384fb9121cf5c81ab30aa4de935246c17/bin/x86_64/read_all | install -m755 /dev/stdin read_all
> > > > >
> > > > > $ sudo sh -c "$PWD/read_all -d /proc && $PWD/read_all -d /sys && dmesg"
> > > > > ...
> > > > > [ 103.605352] BUG: scheduling while atomic: read_all/2907/0x00000002
> > > > > [ 103.605357] Modules linked in: ...
> > > > > [ 103.605401] ...
> > > > > [ 103.605454] CPU: 0 UID: 0 PID: 2907 Comm: read_all Not tainted 6.17.0-rc6-debug-00276-gc4a211c65878 #1 PREEMPT(full) ccfbb8e489d66d107205aa22f3b6242dd3605b88
> > > > > [ 103.605457] Hardware name: AZW MINI S/MINI S, BIOS ADLNV106 05/12/2024
> > > > > [ 103.605459] Call Trace:
> > > > > [ 103.605461] <TASK>
> > > > > [ 103.605465] dump_stack_lvl+0x5d/0x80
> > > > > [ 103.605471] __schedule_bug.cold+0x42/0x4e
> > > > > [ 103.605473] __schedule+0x1083/0x1330
> > > > > [ 103.605478] ? acpi_ex_field_datum_io+0xe8/0x4f0
> > > > > [ 103.605482] ? acpi_os_release_object+0xe/0x20
> > > > > [ 103.605486] schedule+0x27/0xd0
> > > > > [ 103.605487] schedule_timeout+0xbd/0x100
> > > > > [ 103.605491] __down_common+0x137/0x2d0
> > > > > [ 103.605493] down_timeout+0x67/0x70
> > > > > [ 103.605495] acpi_os_wait_semaphore+0x68/0x180
> > > > > [ 103.605498] acpi_ut_acquire_mutex+0x97/0x250
> > > > > [ 103.605500] acpi_ns_delete_namespace_subtree+0x48/0x110
> > > > > [ 103.605503] acpi_ds_terminate_control_method+0x1c8/0x200
> > > > > [ 103.605505] acpi_ps_parse_aml+0x1ae/0x5d0
> > > > > [ 103.605508] acpi_ps_execute_method+0x171/0x3e0
> > > > > [ 103.605511] acpi_ns_evaluate+0x196/0x5c0
> > > > > [ 103.605513] acpi_evaluate_object+0x1ce/0x450
> > > > > [ 103.605515] acpi_evaluate_dsm+0xcb/0x150
> > > > > [ 103.605519] cache_ppi_operations.isra.0+0xc2/0x110
> > > > > [ 103.605522] tpm_show_ppi_tcg_operations+0x99/0xb0
> > > > > [ 103.605523] dev_attr_show+0x1c/0x50
> > > > > [ 103.605526] sysfs_kf_seq_show+0xc9/0x120
> > > > > [ 103.605530] seq_read_iter+0x125/0x480
> > > > > [ 103.605532] ? rw_verify_area+0x56/0x180
> > > > > [ 103.605534] vfs_read+0x265/0x390
> > > > > [ 103.605538] ksys_read+0x73/0xf0
> > > > > [ 103.605540] do_syscall_64+0x81/0x970
> > > > > [ 103.605542] ? ksys_read+0x73/0xf0
> > > > > [ 103.605545] ? refill_obj_stock+0x12e/0x240
> > > > > [ 103.605547] ? xas_load+0xd/0xd0
> > > > > [ 103.605549] ? xa_load+0x76/0xb0
> > > > > [ 103.605552] ? refill_obj_stock+0x12e/0x240
> > > > > [ 103.605553] ? __memcg_slab_free_hook+0xf4/0x140
> > > > > [ 103.605555] ? kmem_cache_free+0x490/0x4d0
> > > > > [ 103.605557] ? __x64_sys_close+0x3d/0x80
> > > > > [ 103.605560] ? __x64_sys_close+0x3d/0x80
> > > > > [ 103.605562] ? do_syscall_64+0x81/0x970
> > > > > [ 103.605563] ? do_syscall_64+0x81/0x970
> > > > > [ 103.605564] ? do_syscall_64+0x81/0x970
> > > > > [ 103.605565] ? do_syscall_64+0x81/0x970
> > > > > [ 103.605566] ? __irq_exit_rcu+0x4c/0xf0
> > > > > [ 103.605569] entry_SYSCALL_64_after_hwframe+0x76/0x7e
> > > > > [ 103.605571] RIP: 0033:0x4243b8
> > > > > [ 103.605597] Code: 0f 05 48 83 f8 da 75 08 4c 89 c0 48 89 d6 0f 05 c3 48 89 f8 4d 89 c2 48 89 f7 4d 89 c8 48 89 d6 4c 8b 4c 24 08 48 89 ca 0f 05 <c3> e9 e1 ff ff ff 48 8d 3d 9b 52 02 00 e9 8a 06 00 00 48 8d 3d 8f
> > > > > [ 103.605598] RSP: 002b:00007ffccef321b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
> > > > > [ 103.605601] RAX: ffffffffffffffda RBX: 00007ffccef32690 RCX: 00000000004243b8
> > > > > [ 103.605602] RDX: 00000000000003ff RSI: 00007ffccef32690 RDI: 0000000000000003
> > > > > [ 103.605603] RBP: 00000000310cdd71 R08: 0000000000000000 R09: 0000000000000000
> > > > > [ 103.605603] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb294164000
> > > > > [ 103.605604] R13: 000000000042b00c R14: 00007ffccef32290 R15: 0000000000000003
> > > > > [ 103.605606] </TASK>
> > > > > [ 103.652735] BUG: scheduling while atomic: read_all/2907/0x00000000
> > > > > [ 103.652739] Modules linked in: ...
> > > > > [ 103.652775] ...
> > > > > [ 103.652825] CPU: 0 UID: 0 PID: 2907 Comm: read_all Tainted: G W 6.17.0-rc6-debug-00276-gc4a211c65878 #1 PREEMPT(full) ccfbb8e489d66d107205aa22f3b6242dd3605b88
> > > > > [ 103.652828] Tainted: [W]=WARN
> > > > > [ 103.652829] Hardware name: AZW MINI S/MINI S, BIOS ADLNV106 05/12/2024
> > > > > [ 103.652830] Call Trace:
> > > > > [ 103.652830] <TASK>
> > > > > [ 103.652831] dump_stack_lvl+0x5d/0x80
> > > > > [ 103.652835] __schedule_bug.cold+0x42/0x4e
> > > > > [ 103.652837] __schedule+0x1083/0x1330
> > > > > [ 103.652840] ? get_nohz_timer_target+0x2f/0x150
> > > > > [ 103.652843] ? timerqueue_add+0x73/0xd0
> > > > > [ 103.652845] schedule+0x27/0xd0
> > > > > [ 103.652847] schedule_hrtimeout_range_clock+0xd8/0x120
> > > > > [ 103.652850] ? __pfx_hrtimer_wakeup+0x10/0x10
> > > > > [ 103.652853] usleep_range_state+0x6c/0xa0
> > > > > [ 103.652855] crb_wait_for_reg_32.constprop.0+0x40/0x80
> > > > > [ 103.652858] crb_request_locality+0x3d/0x50
> > > > > [ 103.652860] tpm_chip_start+0x6c/0xe0
> > > > > [ 103.652862] tpm_try_get_ops+0x89/0xb0
> > > > > [ 103.652863] tpm_find_get_ops+0x1b/0x70
> > > > > [ 103.652865] tpm_pcr_read+0x1b/0x70
> > > > > [ 103.652866] pcr_value_show+0xcc/0x140
> > > > > [ 103.652869] dev_attr_show+0x1c/0x50
> > > > > [ 103.652871] sysfs_kf_seq_show+0xc9/0x120
> > > > > [ 103.652873] seq_read_iter+0x125/0x480
> > > > > [ 103.652875] ? rw_verify_area+0x56/0x180
> > > > > [ 103.652877] vfs_read+0x265/0x390
> > > > > [ 103.652880] ksys_read+0x73/0xf0
> > > > > [ 103.652882] do_syscall_64+0x81/0x970
> > > > > [ 103.652883] ? do_syscall_64+0x81/0x970
> > > > > [ 103.652884] ? __irq_exit_rcu+0x4c/0xf0
> > > > > [ 103.652887] entry_SYSCALL_64_after_hwframe+0x76/0x7e
> > > > > [ 103.652889] RIP: 0033:0x4243b8
> > > > > [ 103.652903] Code: 0f 05 48 83 f8 da 75 08 4c 89 c0 48 89 d6 0f 05 c3 48 89 f8 4d 89 c2 48 89 f7 4d 89 c8 48 89 d6 4c 8b 4c 24 08 48 89 ca 0f 05 <c3> e9 e1 ff ff ff 48 8d 3d 9b 52 02 00 e9 8a 06 00 00 48 8d 3d 8f
> > > > > [ 103.652905] RSP: 002b:00007ffccef321b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
> > > > > [ 103.652906] RAX: ffffffffffffffda RBX: 00007ffccef32690 RCX: 00000000004243b8
> > > > > [ 103.652907] RDX: 00000000000003ff RSI: 00007ffccef32690 RDI: 0000000000000003
> > > > > [ 103.652908] RBP: 00000000310cdd71 R08: 0000000000000000 R09: 0000000000000000
> > > > > [ 103.652909] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb294164000
> > > > > [ 103.652910] R13: 000000000042b00c R14: 00007ffccef32290 R15: 0000000000000003
> > > > > [ 103.652912] </TASK>
> > > > >
> > > > > If there is any other information I can provide or patches I can test, I
> > > > > am more than happy to do so.
>
> Hi Nathan, thank you so much for the catch!
>
> > > >
> > > > Thanks a lot! And I have not rushed with my 6.18 pull request.
> > > >
> > > > It took me less than 30 seconds to locate the bug: it's spin
> > > > lock and sleeing operations.
> > > >
> > > > E.g., acpi_evaluate_dsm_typed can lead to kzalloc() and stuff
> > > > like that. I don't know how I could I have possibly missed this
> > > > detail and this is embarrasing but luckily this should be easy
> > > > to fix with major hurdle :-)
> > > >
> > > > What I suggest is that I'll simply repeal and replace the lock
> > > > type (i.e. tweak the patch), as it does not feel worth of trouble
> > > > to do a review round. Then we should be seeing better results.
> > > >
> > > > Thanks again for spotting this. Yeah, and definitely not blaming
> > > > original author for this. It's all on me tbh. The patch itself
> > > > was great and I should have been able to address this...
> > >
> > >
> > > So I guess the fix is exactly this:
> > >
> > > ~/work/kernel.org/jarkko/linux-tpmdd master* ⇡⇣
> > > ❯ sed -i 's/DEFINE_SPINLOCK/DEFINE_MUTEX/g' drivers/char/tpm/tpm_ppi.c
> > >
> > > ~/work/kernel.org/jarkko/linux-tpmdd master* ⇡⇣
> > > ❯ sed -i 's/spin_/mutex_/g' drivers/char/tpm/tpm_ppi.c
> > >
> > > ~/work/kernel.org/jarkko/linux-tpmdd master* ⇡⇣
> > > ❯ git -P diff
> > > diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c
> > > index 47655407fea5..c9793a3d986d 100644
> > > --- a/drivers/char/tpm/tpm_ppi.c
> > > +++ b/drivers/char/tpm/tpm_ppi.c
> > > @@ -42,7 +42,7 @@ static const char * const tpm_ppi_info[] = {
> > > };
> > >
> > > /* A spinlock to protect access to the cache from concurrent reads */
>
> Hi Jarkko, this comment should be updated if it's not too late.
Shouldn't be a problem as long as the fix is good.
>
> > > -static DEFINE_SPINLOCK(tpm_ppi_lock);
> > > +static DEFINE_MUTEX(tpm_ppi_lock);
> > >
> > > static u32 ppi_operations_cache[PPI_VS_REQ_END + 1];
> > > static bool ppi_cache_populated;
> > > @@ -329,11 +329,11 @@ static ssize_t tpm_show_ppi_tcg_operations(struct device *dev,
> > > u32 ret;
> > > int i;
> > >
> > > - spin_lock(&tpm_ppi_lock);
> > > + mutex_lock(&tpm_ppi_lock);
> > > if (!ppi_cache_populated) {
> > > len = cache_ppi_operations(chip->acpi_dev_handle, buf);
> > > if (len < 0) {
> > > - spin_unlock(&tpm_ppi_lock);
> > > + mutex_unlock(&tpm_ppi_lock);
> > > return len;
> > > }
> > >
> > > @@ -346,7 +346,7 @@ static ssize_t tpm_show_ppi_tcg_operations(struct device *dev,
> > > len += sysfs_emit_at(buf, len, "%d %d: %s\n",
> > > i, ret, tpm_ppi_info[ret]);
> > > }
> > > - spin_unlock(&tpm_ppi_lock);
> > > + mutex_unlock(&tpm_ppi_lock);
> > >
> > > return len;
> > > }
> > > @@ -360,11 +360,11 @@ static ssize_t tpm_show_ppi_vs_operations(struct device *dev,
> > > u32 ret;
> > > int i;
> > >
> > > - spin_lock(&tpm_ppi_lock);
> > > + mutex_lock(&tpm_ppi_lock);
> > > if (!ppi_cache_populated) {
> > > len = cache_ppi_operations(chip->acpi_dev_handle, buf);
> > > if (len < 0) {
> > > - spin_unlock(&tpm_ppi_lock);
> > > + mutex_unlock(&tpm_ppi_lock);
> > > return len;
> > > }
> > >
> > > @@ -377,7 +377,7 @@ static ssize_t tpm_show_ppi_vs_operations(struct device *dev,
> > > len += sysfs_emit_at(buf, len, "%d %d: %s\n",
> > > i, ret, tpm_ppi_info[ret]);
> > > }
> > > - spin_unlock(&tpm_ppi_lock);
> > > + mutex_unlock(&tpm_ppi_lock);
> > >
> > > return len;
> > > }
> > >
> > > I'll just push it to next as it does not make things worse and
> > > right at the moment I don't have time to do conclusive testing
> > > (and it is high certainty the correct fix).
> >
> > https://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git/commit/?h=next&id=7e93fe26caa9c010d438b267616793026db363b7
>
> Many thanks for the quick fix! I also should have seen this ahead of time.
Yeah, np, I mean even if this had landed it would have been quickly
fixed up. Not really catastrophe, this type of things happen...
>
> >
> > BR, Jarkko
> >
>
> Best,
> Denis
>
BR, Jarkko
prev parent reply other threads:[~2025-09-24 17:04 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-15 21:08 [PATCH v5] tpm: Prevent local DOS via tpm/tpm0/ppi/*operations Denis Aleksandrov
2025-09-16 2:04 ` Jarkko Sakkinen
2025-09-16 14:13 ` Denis Aleksandrov
2025-09-18 14:34 ` Jarkko Sakkinen
2025-09-23 20:07 ` Nathan Chancellor
2025-09-24 0:57 ` Jarkko Sakkinen
2025-09-24 3:31 ` Jarkko Sakkinen
2025-09-24 3:37 ` Jarkko Sakkinen
2025-09-24 7:34 ` Denis Aleksandrov
2025-09-24 17:04 ` Jarkko Sakkinen [this message]
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