From: Benjamin Bara <benjamin.bara@skidata.com> stable inclusion from stable-v5.10.202 commit 25284c46b657f48c0f3880a2e0706c70d81182c0 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9RFEQ CVE: CVE-2023-52791 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit aa49c90894d06e18a1ee7c095edbd2f37c232d02 upstream. Since bae1d3a05a8b, i2c transfers are non-atomic if preemption is disabled. However, non-atomic i2c transfers require preemption (e.g. in wait_for_completion() while waiting for the DMA). panic() calls preempt_disable_notrace() before calling emergency_restart(). Therefore, if an i2c device is used for the restart, the xfer should be atomic. This avoids warnings like: [ 12.667612] WARNING: CPU: 1 PID: 1 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x33c/0x6b0 [ 12.676926] Voluntary context switch within RCU read-side critical section! ... [ 12.742376] schedule_timeout from wait_for_completion_timeout+0x90/0x114 [ 12.749179] wait_for_completion_timeout from tegra_i2c_wait_completion+0x40/0x70 ... [ 12.994527] atomic_notifier_call_chain from machine_restart+0x34/0x58 [ 13.001050] machine_restart from panic+0x2a8/0x32c Use !preemptible() instead, which is basically the same check as pre-v5.2. Fixes: bae1d3a05a8b ("i2c: core: remove use of in_atomic()") Cc: stable@vger.kernel.org # v5.2+ Suggested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Acked-by: Wolfram Sang <wsa@kernel.org> Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Tested-by: Nishanth Menon <nm@ti.com> Signed-off-by: Benjamin Bara <benjamin.bara@skidata.com> Link: https://lore.kernel.org/r/20230327-tegra-pmic-reboot-v7-2-18699d5dcd76@skida... Signed-off-by: Lee Jones <lee@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Kaixiong Yu <yukaixiong@huawei.com> --- drivers/i2c/i2c-core.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h index 8ce261167a2d..ea17f13b44c8 100644 --- a/drivers/i2c/i2c-core.h +++ b/drivers/i2c/i2c-core.h @@ -29,7 +29,7 @@ int i2c_dev_irq_from_resources(const struct resource *resources, */ static inline bool i2c_in_atomic_xfer_mode(void) { - return system_state > SYSTEM_RUNNING && irqs_disabled(); + return system_state > SYSTEM_RUNNING && !preemptible(); } static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap) -- 2.25.1