| Message ID | 1530695020-21888-1-git-send-email-shirish.s@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jul 04, 2018 at 02:33:40PM +0530, Shirish S wrote: > During system shutdown, > tpm_class_shutdown() when called with TPM_CHIP_FLAG_TPM2 > flag set, makes chip->ops NULL. > > However tpm_chip_unregister() called later in shutdown > sequence tries to access chip->ops in tpm_try_transmit() > leading the NULL pointer dereference. > > This patch fixes this issue. > Below is the trace for reference: > > BUG: unable to handle kernel NULL pointer dereference at > 0000000000000048 > IP: tpm_transmit+0x267/0x565 > PGD 0 P4D 0 > Oops: 0000 [#1] PREEMPT SMP NOPTI > ... > task: ffff937c847fe580 task.stack: ffffa79f80b04000 > RIP: 0010:tpm_transmit+0x267/0x565 > RSP: 0018:ffffa79f80b07c08 EFLAGS: 00010286 > RAX: 0000000000000000 RBX: ffff937ca9bc8000 RCX: ffff937c847fe580 > RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffffffff98e3cd40 > RBP: ffffa79f80b07c88 R08: 000000000001fff4 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: ffffa79f80b07cd4 > R13: 000000000000008c R14: ffffffffffffffc3 R15: 0000000000000000 > FS: 00007ef31f747740(0000) GS:ffff937caed00000(0000) > knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000048 CR3: 00000001243d2000 CR4: 00000000001406e0 > Call Trace: > tpm_transmit_cmd+0x25/0x70 > tpm2_shutdown+0x69/0xa3 > ? __radix_tree_replace+0xd9/0x120 > ? idr_replace_ext+0x92/0xb6 > tpm_chip_unregister+0xaa/0xdb > cr50_i2c_shutdown+0x1e/0x41 It makes no sense to call something like tpm_unregister from shutdown. Jason
On Wed, Jul 04, 2018 at 02:33:40PM +0530, Shirish S wrote: > During system shutdown, > tpm_class_shutdown() when called with TPM_CHIP_FLAG_TPM2 > flag set, makes chip->ops NULL. > > However tpm_chip_unregister() called later in shutdown > sequence tries to access chip->ops in tpm_try_transmit() > leading the NULL pointer dereference. > > This patch fixes this issue. > Below is the trace for reference: > > BUG: unable to handle kernel NULL pointer dereference at > 0000000000000048 > IP: tpm_transmit+0x267/0x565 > PGD 0 P4D 0 > Oops: 0000 [#1] PREEMPT SMP NOPTI > ... > task: ffff937c847fe580 task.stack: ffffa79f80b04000 > RIP: 0010:tpm_transmit+0x267/0x565 > RSP: 0018:ffffa79f80b07c08 EFLAGS: 00010286 > RAX: 0000000000000000 RBX: ffff937ca9bc8000 RCX: ffff937c847fe580 > RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffffffff98e3cd40 > RBP: ffffa79f80b07c88 R08: 000000000001fff4 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: ffffa79f80b07cd4 > R13: 000000000000008c R14: ffffffffffffffc3 R15: 0000000000000000 > FS: 00007ef31f747740(0000) GS:ffff937caed00000(0000) > knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000048 CR3: 00000001243d2000 CR4: 00000000001406e0 > Call Trace: > tpm_transmit_cmd+0x25/0x70 > tpm2_shutdown+0x69/0xa3 > ? __radix_tree_replace+0xd9/0x120 > ? idr_replace_ext+0x92/0xb6 > tpm_chip_unregister+0xaa/0xdb > cr50_i2c_shutdown+0x1e/0x41 > device_shutdown+0x157/0x193 > kernel_power_off+0x35/0x6e > SYSC_reboot+0x120/0x1a3 > ? do_writepages+0x36/0x6e > ? do_writepages+0x36/0x6e > ? sync_inodes_one_sb+0x17/0x17 > ? _raw_spin_unlock+0xe/0x20 > ? iput+0x87/0x1bd > do_syscall_64+0x64/0x72 > entry_SYSCALL_64_after_hwframe+0x3d/0xa2 > > Signed-off-by: Shirish S <shirish.s@amd.com> > --- > drivers/char/tpm/tpm-interface.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > index e32f6e8..b14d196 100644 > --- a/drivers/char/tpm/tpm-interface.c > +++ b/drivers/char/tpm/tpm-interface.c > @@ -411,6 +411,14 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, > unsigned long stop; > bool need_locality; > > + /* chip->ops is made NULL in tpm_class_shutdown() > + * This case is hit when tpm_chip_unregister() is called post > + * tpm_class_shutdown(), hence exit early and return > + * transmit operation not permitted > + */ > + if (!chip->ops) > + return -EPERM; > + > rc = tpm_validate_command(chip, space, buf, bufsiz); > if (rc == -EINVAL) > return rc; > -- > 2.7.4 > What is cr50 anyway? /Jarkko
On 7/4/2018 10:43 PM, Jarkko Sakkinen wrote: > On Wed, Jul 04, 2018 at 02:33:40PM +0530, Shirish S wrote: >> During system shutdown, >> tpm_class_shutdown() when called with TPM_CHIP_FLAG_TPM2 >> flag set, makes chip->ops NULL. >> >> However tpm_chip_unregister() called later in shutdown >> sequence tries to access chip->ops in tpm_try_transmit() >> leading the NULL pointer dereference. >> >> This patch fixes this issue. >> Below is the trace for reference: >> >> BUG: unable to handle kernel NULL pointer dereference at >> 0000000000000048 >> IP: tpm_transmit+0x267/0x565 >> PGD 0 P4D 0 >> Oops: 0000 [#1] PREEMPT SMP NOPTI >> ... >> task: ffff937c847fe580 task.stack: ffffa79f80b04000 >> RIP: 0010:tpm_transmit+0x267/0x565 >> RSP: 0018:ffffa79f80b07c08 EFLAGS: 00010286 >> RAX: 0000000000000000 RBX: ffff937ca9bc8000 RCX: ffff937c847fe580 >> RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffffffff98e3cd40 >> RBP: ffffa79f80b07c88 R08: 000000000001fff4 R09: 0000000000000000 >> R10: 0000000000000000 R11: 0000000000000000 R12: ffffa79f80b07cd4 >> R13: 000000000000008c R14: ffffffffffffffc3 R15: 0000000000000000 >> FS: 00007ef31f747740(0000) GS:ffff937caed00000(0000) >> knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 0000000000000048 CR3: 00000001243d2000 CR4: 00000000001406e0 >> Call Trace: >> tpm_transmit_cmd+0x25/0x70 >> tpm2_shutdown+0x69/0xa3 >> ? __radix_tree_replace+0xd9/0x120 >> ? idr_replace_ext+0x92/0xb6 >> tpm_chip_unregister+0xaa/0xdb >> cr50_i2c_shutdown+0x1e/0x41 >> device_shutdown+0x157/0x193 >> kernel_power_off+0x35/0x6e >> SYSC_reboot+0x120/0x1a3 >> ? do_writepages+0x36/0x6e >> ? do_writepages+0x36/0x6e >> ? sync_inodes_one_sb+0x17/0x17 >> ? _raw_spin_unlock+0xe/0x20 >> ? iput+0x87/0x1bd >> do_syscall_64+0x64/0x72 >> entry_SYSCALL_64_after_hwframe+0x3d/0xa2 >> >> Signed-off-by: Shirish S <shirish.s@amd.com> >> --- >> drivers/char/tpm/tpm-interface.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c >> index e32f6e8..b14d196 100644 >> --- a/drivers/char/tpm/tpm-interface.c >> +++ b/drivers/char/tpm/tpm-interface.c >> @@ -411,6 +411,14 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, >> unsigned long stop; >> bool need_locality; >> >> + /* chip->ops is made NULL in tpm_class_shutdown() >> + * This case is hit when tpm_chip_unregister() is called post >> + * tpm_class_shutdown(), hence exit early and return >> + * transmit operation not permitted >> + */ >> + if (!chip->ops) >> + return -EPERM; >> + >> rc = tpm_validate_command(chip, space, buf, bufsiz); >> if (rc == -EINVAL) >> return rc; >> -- >> 2.7.4 >> > What is cr50 anyway? Please ignore this patch, i realised the cr50 is not yet upstreamed. Hence the issue lies in in cr50 and not tpm driver. Thanks. Regards, Shirish S > /Jarkko
On Thu, Jul 05, 2018 at 09:29:34AM +0530, S, Shirish wrote: > > > On 7/4/2018 10:43 PM, Jarkko Sakkinen wrote: > > On Wed, Jul 04, 2018 at 02:33:40PM +0530, Shirish S wrote: > > > During system shutdown, > > > tpm_class_shutdown() when called with TPM_CHIP_FLAG_TPM2 > > > flag set, makes chip->ops NULL. > > > > > > However tpm_chip_unregister() called later in shutdown > > > sequence tries to access chip->ops in tpm_try_transmit() > > > leading the NULL pointer dereference. > > > > > > This patch fixes this issue. > > > Below is the trace for reference: > > > > > > BUG: unable to handle kernel NULL pointer dereference at > > > 0000000000000048 > > > IP: tpm_transmit+0x267/0x565 > > > PGD 0 P4D 0 > > > Oops: 0000 [#1] PREEMPT SMP NOPTI > > > ... > > > task: ffff937c847fe580 task.stack: ffffa79f80b04000 > > > RIP: 0010:tpm_transmit+0x267/0x565 > > > RSP: 0018:ffffa79f80b07c08 EFLAGS: 00010286 > > > RAX: 0000000000000000 RBX: ffff937ca9bc8000 RCX: ffff937c847fe580 > > > RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffffffff98e3cd40 > > > RBP: ffffa79f80b07c88 R08: 000000000001fff4 R09: 0000000000000000 > > > R10: 0000000000000000 R11: 0000000000000000 R12: ffffa79f80b07cd4 > > > R13: 000000000000008c R14: ffffffffffffffc3 R15: 0000000000000000 > > > FS: 00007ef31f747740(0000) GS:ffff937caed00000(0000) > > > knlGS:0000000000000000 > > > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > > > CR2: 0000000000000048 CR3: 00000001243d2000 CR4: 00000000001406e0 > > > Call Trace: > > > tpm_transmit_cmd+0x25/0x70 > > > tpm2_shutdown+0x69/0xa3 > > > ? __radix_tree_replace+0xd9/0x120 > > > ? idr_replace_ext+0x92/0xb6 > > > tpm_chip_unregister+0xaa/0xdb > > > cr50_i2c_shutdown+0x1e/0x41 > > > device_shutdown+0x157/0x193 > > > kernel_power_off+0x35/0x6e > > > SYSC_reboot+0x120/0x1a3 > > > ? do_writepages+0x36/0x6e > > > ? do_writepages+0x36/0x6e > > > ? sync_inodes_one_sb+0x17/0x17 > > > ? _raw_spin_unlock+0xe/0x20 > > > ? iput+0x87/0x1bd > > > do_syscall_64+0x64/0x72 > > > entry_SYSCALL_64_after_hwframe+0x3d/0xa2 > > > > > > Signed-off-by: Shirish S <shirish.s@amd.com> > > > --- > > > drivers/char/tpm/tpm-interface.c | 8 ++++++++ > > > 1 file changed, 8 insertions(+) > > > > > > diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c > > > index e32f6e8..b14d196 100644 > > > --- a/drivers/char/tpm/tpm-interface.c > > > +++ b/drivers/char/tpm/tpm-interface.c > > > @@ -411,6 +411,14 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, > > > unsigned long stop; > > > bool need_locality; > > > + /* chip->ops is made NULL in tpm_class_shutdown() > > > + * This case is hit when tpm_chip_unregister() is called post > > > + * tpm_class_shutdown(), hence exit early and return > > > + * transmit operation not permitted > > > + */ > > > + if (!chip->ops) > > > + return -EPERM; > > > + > > > rc = tpm_validate_command(chip, space, buf, bufsiz); > > > if (rc == -EINVAL) > > > return rc; > > > -- > > > 2.7.4 > > > > > What is cr50 anyway? > Please ignore this patch, i realised the cr50 is not yet upstreamed. > Hence the issue lies in in cr50 and not tpm driver. > Thanks. > Regards, > Shirish S tpm_chip_unregister() in supposed to be called only in removal/detach sequence so the root cause for the NULL pointer deref is the driver, not the existing TPM stack. /Jarkko
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index e32f6e8..b14d196 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -411,6 +411,14 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip, unsigned long stop; bool need_locality; + /* chip->ops is made NULL in tpm_class_shutdown() + * This case is hit when tpm_chip_unregister() is called post + * tpm_class_shutdown(), hence exit early and return + * transmit operation not permitted + */ + if (!chip->ops) + return -EPERM; + rc = tpm_validate_command(chip, space, buf, bufsiz); if (rc == -EINVAL) return rc;
During system shutdown, tpm_class_shutdown() when called with TPM_CHIP_FLAG_TPM2 flag set, makes chip->ops NULL. However tpm_chip_unregister() called later in shutdown sequence tries to access chip->ops in tpm_try_transmit() leading the NULL pointer dereference. This patch fixes this issue. Below is the trace for reference: BUG: unable to handle kernel NULL pointer dereference at 0000000000000048 IP: tpm_transmit+0x267/0x565 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP NOPTI ... task: ffff937c847fe580 task.stack: ffffa79f80b04000 RIP: 0010:tpm_transmit+0x267/0x565 RSP: 0018:ffffa79f80b07c08 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff937ca9bc8000 RCX: ffff937c847fe580 RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffffffff98e3cd40 RBP: ffffa79f80b07c88 R08: 000000000001fff4 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffa79f80b07cd4 R13: 000000000000008c R14: ffffffffffffffc3 R15: 0000000000000000 FS: 00007ef31f747740(0000) GS:ffff937caed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000048 CR3: 00000001243d2000 CR4: 00000000001406e0 Call Trace: tpm_transmit_cmd+0x25/0x70 tpm2_shutdown+0x69/0xa3 ? __radix_tree_replace+0xd9/0x120 ? idr_replace_ext+0x92/0xb6 tpm_chip_unregister+0xaa/0xdb cr50_i2c_shutdown+0x1e/0x41 device_shutdown+0x157/0x193 kernel_power_off+0x35/0x6e SYSC_reboot+0x120/0x1a3 ? do_writepages+0x36/0x6e ? do_writepages+0x36/0x6e ? sync_inodes_one_sb+0x17/0x17 ? _raw_spin_unlock+0xe/0x20 ? iput+0x87/0x1bd do_syscall_64+0x64/0x72 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Signed-off-by: Shirish S <shirish.s@amd.com> --- drivers/char/tpm/tpm-interface.c | 8 ++++++++ 1 file changed, 8 insertions(+)