From be13e3e0c1027249b6aec4e82736b0344add6b67 Mon Sep 17 00:00:00 2001 From: Benjamin Bara Date: Sat, 15 Jul 2023 09:53:24 +0200 Subject: [PATCH 1/2] i2c: core: Run atomic i2c xfer when !preemptible stable inclusion from stable-5.10.202 commit 25284c46b657f48c0f3880a2e0706c70d81182c0 category: bugfix issue: NA CVE: CVE-2023-52791 Signed-off-by: wanxiaoqing --------------------------------------- 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 Acked-by: Wolfram Sang Reviewed-by: Dmitry Osipenko Tested-by: Nishanth Menon Signed-off-by: Benjamin Bara Link: https://lore.kernel.org/r/20230327-tegra-pmic-reboot-v7-2-18699d5dcd76@skidata.com Signed-off-by: Lee Jones Signed-off-by: Greg Kroah-Hartman Signed-off-by: wanxiaoqing --- 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) -- Gitee From b44129434d9ce8f0375fc9817c8dde7dfed48287 Mon Sep 17 00:00:00 2001 From: Benjamin Bara Date: Thu, 4 Jan 2024 09:17:08 +0100 Subject: [PATCH 2/2] i2c: core: Fix atomic xfer check for non-preempt config stable inclusion from stable-5.10.208 commit 4aca0af44721fbbbf619fddca6c41ff84fbf2170 category: bugfix issue: NA CVE: NA Signed-off-by: wanxiaoqing --------------------------------------- commit a3368e1186e3ce8e38f78cbca019622095b1f331 upstream. Since commit aa49c90894d0 ("i2c: core: Run atomic i2c xfer when !preemptible"), the whole reboot/power off sequence on non-preempt kernels is using atomic i2c xfer, as !preemptible() always results to 1. During device_shutdown(), the i2c might be used a lot and not all busses have implemented an atomic xfer handler. This results in a lot of avoidable noise, like: [ 12.687169] No atomic I2C transfer handler for 'i2c-0' [ 12.692313] WARNING: CPU: 6 PID: 275 at drivers/i2c/i2c-core.h:40 i2c_smbus_xfer+0x100/0x118 ... Fix this by allowing non-atomic xfer when the interrupts are enabled, as it was before. Link: https://lore.kernel.org/r/20231222230106.73f030a5@yea Link: https://lore.kernel.org/r/20240102150350.3180741-1-mwalle@kernel.org Link: https://lore.kernel.org/linux-i2c/13271b9b-4132-46ef-abf8-2c311967bb46@mailbox.org/ Fixes: aa49c90894d0 ("i2c: core: Run atomic i2c xfer when !preemptible") Cc: stable@vger.kernel.org # v5.2+ Signed-off-by: Benjamin Bara Tested-by: Michael Walle Tested-by: Tor Vic [wsa: removed a comment which needs more work, code is ok] Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman Signed-off-by: wanxiaoqing --- drivers/i2c/i2c-core.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h index ea17f13b44c8..ec28024a646d 100644 --- a/drivers/i2c/i2c-core.h +++ b/drivers/i2c/i2c-core.h @@ -3,6 +3,7 @@ * i2c-core.h - interfaces internal to the I2C framework */ +#include #include struct i2c_devinfo { @@ -29,7 +30,8 @@ int i2c_dev_irq_from_resources(const struct resource *resources, */ static inline bool i2c_in_atomic_xfer_mode(void) { - return system_state > SYSTEM_RUNNING && !preemptible(); + return system_state > SYSTEM_RUNNING && + (IS_ENABLED(CONFIG_PREEMPT_COUNT) ? !preemptible() : irqs_disabled()); } static inline int __i2c_lock_bus_helper(struct i2c_adapter *adap) -- Gitee