This is an automated email from Gerrit. "Tomas Vanek <van...@fbl.cz>" just uploaded a new patch set to Gerrit, which you can find at https://review.openocd.org/c/openocd/+/7108
-- gerrit commit b5de26a996b461e0c619522b2643a136634d2ee0 Author: Tomas Vanek <van...@fbl.cz> Date: Tue Aug 2 11:33:07 2022 +0200 target/cortex_m: prevent segmentation fault in cortex_m_poll() If a Cortex-M MCU become unresponsive during a debug session and re-examination fails to find MEM-AP, debug_ap pointer is set to NULL. Eventual call of cortex_m_poll() dereferences debug_ap. Check debug_ap validity at the begin of cortex_m_poll(). Change-Id: I9519f48760c91a48a9e5e8c34634d247098cb14a Signed-off-by: Tomas Vanek <van...@fbl.cz> diff --git a/src/target/cortex_m.c b/src/target/cortex_m.c index 1682f5dec9..9497aa0373 100644 --- a/src/target/cortex_m.c +++ b/src/target/cortex_m.c @@ -868,6 +868,16 @@ static int cortex_m_poll(struct target *target) struct cortex_m_common *cortex_m = target_to_cm(target); struct armv7m_common *armv7m = &cortex_m->armv7m; + /* Check if debug_ap is available to prevent segmentation fault. + * If the re-examination after an error does not find a MEM-AP + * (e.g. the target stopped communicating), debug_ap pointer + * can suddenly become NULL. + */ + if (!armv7m->debug_ap) { + target->state = TARGET_UNKNOWN; + return ERROR_TARGET_NOT_EXAMINED; + } + /* Read from Debug Halting Control and Status Register */ retval = cortex_m_read_dhcsr_atomic_sticky(target); if (retval != ERROR_OK) { --