Since 68ed819 "acpi-spmi locate driver" the initialization of acpi_table was done as a direct assignment on a global variable. Later on _ipmi_acpi_get_table was restructured and now expects malloced memory, but the old intialization was left in place now killing the malloced pointer.
It turns out that on systems without /sys/firmware/acpi/tables/SPMI like Dell iDRAC6/9 _ipmi_acpi_get_table then tries to assign acpi_table_buf to it. This leads to an access of 0x0 and a crash, for a backtrace see: https://launchpadlibrarian.net/495892193/apport-retrace-ipmi-locate.txt On other hardware (with SPMI file in sysfs) there are some early exits before this happens. Additionally Before 094cd5ce "Audit libfreeipmi, remove unnecessary memsets, fix +1 buffers, etc." which is in >1.6.0 there was another early exit in _ipmi_acpi_get_table_dev_mem as _ipmi_acpi_get_rsdp never returned non zero, but since that fix it can reach the bad code. The old style assignment of acpi_table is wrong (writes the pointer instead of the pointer target) and superfluous as it is done correct at the beginning of _ipmi_acpi_get_table_dev_mem and between this init and the usage no more touched. Therefore it is safe to just remove the bad initialization. Signed-off-by: Christian Ehrhardt <christian.ehrha...@canonical.com> Reported-by: jeffrey.l...@canonical.com --- libfreeipmi/locate/ipmi-locate-acpi-spmi.c | 1 - 1 file changed, 1 deletion(-) diff --git a/libfreeipmi/locate/ipmi-locate-acpi-spmi.c b/libfreeipmi/locate/ipmi-locate-acpi-spmi.c index 710674e53..11c688524 100644 --- a/libfreeipmi/locate/ipmi-locate-acpi-spmi.c +++ b/libfreeipmi/locate/ipmi-locate-acpi-spmi.c @@ -1384,7 +1384,6 @@ _ipmi_acpi_get_table_dev_mem (ipmi_locate_ctx_t ctx, else acpi_table_count = rsdt_xsdt_table_data_length / 8; - acpi_table = NULL; acpi_table_length = 0; for (i = 0, signature_table_count = 0; i < acpi_table_count; i++) { -- 2.28.0