diff options
| author | Vasily Gorbik <gor@linux.ibm.com> | 2026-08-13 13:06:54 +0200 |
|---|---|---|
| committer | Heiko Carstens <hca@linux.ibm.com> | 2026-08-31 16:25:38 +0200 |
| commit | 7f918871112e8e7c581e99eb8e545af4e59c8367 (patch) | |
| tree | 2be1824cd8efc3efdcecd829612f9261eac15a07 | |
| parent | f3c63b8cabbb121866347fe164c23635965b31d7 (diff) | |
s390/ipl: Fix NULL deref in kdump without re-IPL parm block
Some IPL types, like HMC FTP boot or QEMU direct kernel boot, might
not provide an IPL parameter block. In this case, reipl_type_init()
selects IPL_TYPE_UNKNOWN, and reipl_block_actual remains NULL.
kdump passes the re-IPL parameter block to the dump kernel through
os_info. Before commit 3b9678472bab ("s390/ipl: correct kdump reipl
block checksum calculation"), the os_info entry was added only for
IPL types which initialized reipl_block_actual. That commit moved the
os_info update to machine_crash_shutdown(), making it unconditional. As
a result, set_os_info_reipl_block() dereferences reipl_block_actual for
IPL_TYPE_UNKNOWN. This may happen to work by chance when address zero
contains readable lowcore data and the resulting empty os_info entry is
ignored by the dump kernel.
Skip the os_info update when no re-IPL parameter block is available.
Kdump then collect the dump and reboot without setting re-IPL parameter
block.
Fixes: 3b9678472bab ("s390/ipl: correct kdump reipl block checksum calculation")
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
| -rw-r--r-- | arch/s390/kernel/ipl.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c index d74ef30155aa..8c672e36b397 100644 --- a/arch/s390/kernel/ipl.c +++ b/arch/s390/kernel/ipl.c @@ -1157,6 +1157,8 @@ static struct attribute_group reipl_nss_attr_group = { void set_os_info_reipl_block(void) { + if (!reipl_block_actual) + return; os_info_entry_add_data(OS_INFO_REIPL_BLOCK, reipl_block_actual, reipl_block_actual->hdr.len); } |