Уязвимость функции hso_serial_tty_unregister драйвера USB HSO (High Speed Options) ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

Уязвимость функции queued_write_lock_slowpath() компонента locking/qrwlock.c ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании

Уязвимость функции tpm2_seal_trusted() модуля security/keys/trusted-keys/trusted_tpm2.c ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании.

In the Linux kernel, the following vulnerability has been resolved: net: hso: fix NULL-deref on disconnect regression Commit 8a12f8836145 ("net: hso: fix null-ptr-deref during tty device unregistration") fixed the racy minor allocation reported by syzbot, but introduced an unconditional NULL-pointer dereference on every disconnect instead. Specifically, the serial device table must no longer be accessed after the minor has been released by hso_serial_tty_unregister().

In the Linux kernel, the following vulnerability has been resolved: locking/qrwlock: Fix ordering in queued_write_lock_slowpath() While this code is executed with the wait_lock held, a reader can acquire the lock without holding wait_lock. The writer side loops checking the value with the atomic_cond_read_acquire(), but only truly acquires the lock when the compare-and-exchange is completed successfully which isn’t ordered. This exposes the window between the acquire and the cmpxchg to an A-B-A problem which allows reads following the lock acquisition to observe values speculatively before the write lock is truly acquired. We've seen a problem in epoll where the reader does a xchg while holding the read lock, but the writer can see a value change out from under it. Writer | Reader -------------------------------------------------------------------------------- ep_scan_ready_list() | |- write_lock_irq() | |- queued_write_lock_slowpath() | |- atomic_cond_read_acquire() | | read_lock_irqsave(&ep->lock, flags); --> (observes value before unlock) | chain_epi_lockless() | | epi->next = xchg(&ep->ovflist, epi); | | read_unlock_irqrestore(&ep->lock, flags); | | | atomic_cmpxchg_relaxed() | |-- READ_ONCE(ep->ovflist); | A core can order the read of the ovflist ahead of the atomic_cmpxchg_relaxed(). Switching the cmpxchg to use acquire semantics addresses this issue at which point the atomic_cond_read can be switched to use relaxed semantics. [peterz: use try_cmpxchg()]

In the Linux kernel, the following vulnerability has been resolved: KEYS: trusted: Fix TPM reservation for seal/unseal The original patch 8c657a0590de ("KEYS: trusted: Reserve TPM for seal and unseal operations") was correct on the mailing list: https://lore.kernel.org/linux-integrity/20210128235621.127925-4-jarkko@kernel.org/ But somehow got rebased so that the tpm_try_get_ops() in tpm2_seal_trusted() got lost. This causes an imbalanced put of the TPM ops and causes oopses on TIS based hardware. This fix puts back the lost tpm_try_get_ops()