From: "Dr. David Alan Gilbert" <dgilb...@redhat.com> and use it in loadvm_state and ram_load.
Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com> --- arch_init.c | 5 +---- include/migration/qemu-file.h | 3 +++ migration/qemu-file.c | 16 ++++++++++++++++ savevm.c | 11 ++++++----- 4 files changed, 26 insertions(+), 9 deletions(-) diff --git a/arch_init.c b/arch_init.c index 4c8fcee..06722bb 100644 --- a/arch_init.c +++ b/arch_init.c @@ -1145,13 +1145,10 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id) total_ram_bytes = addr; while (!ret && total_ram_bytes) { RAMBlock *block; - uint8_t len; char id[256]; ram_addr_t length; - len = qemu_get_byte(f); - qemu_get_buffer(f, (uint8_t *)id, len); - id[len] = 0; + qemu_get_counted_string(f, id); length = qemu_get_be64(f); QLIST_FOREACH_RCU(block, &ram_list.blocks, next) { diff --git a/include/migration/qemu-file.h b/include/migration/qemu-file.h index 745a850..236a2e4 100644 --- a/include/migration/qemu-file.h +++ b/include/migration/qemu-file.h @@ -309,4 +309,7 @@ static inline void qemu_get_sbe64s(QEMUFile *f, int64_t *pv) { qemu_get_be64s(f, (uint64_t *)pv); } + +int qemu_get_counted_string(QEMUFile *f, char buf[256]); + #endif diff --git a/migration/qemu-file.c b/migration/qemu-file.c index 1a4f986..6c18e55 100644 --- a/migration/qemu-file.c +++ b/migration/qemu-file.c @@ -546,3 +546,19 @@ uint64_t qemu_get_be64(QEMUFile *f) v |= qemu_get_be32(f); return v; } + +/* + * Get a string whose length is determined by a single preceding byte + * A preallocated 256 byte buffer must be passed in. + * Returns: 0 on success and a 0 terminated string in the buffer + */ +int qemu_get_counted_string(QEMUFile *f, char buf[256]) +{ + unsigned int len = qemu_get_byte(f); + int res = qemu_get_buffer(f, (uint8_t *)buf, len); + + buf[len] = 0; + + return res != len; +} + diff --git a/savevm.c b/savevm.c index c08abcc..9795e2e 100644 --- a/savevm.c +++ b/savevm.c @@ -969,8 +969,7 @@ int qemu_loadvm_state(QEMUFile *f) while ((section_type = qemu_get_byte(f)) != QEMU_VM_EOF) { uint32_t instance_id, version_id, section_id; SaveStateEntry *se; - char idstr[257]; - int len; + char idstr[256]; trace_qemu_loadvm_state_section(section_type); switch (section_type) { @@ -978,9 +977,11 @@ int qemu_loadvm_state(QEMUFile *f) case QEMU_VM_SECTION_FULL: /* Read section start */ section_id = qemu_get_be32(f); - len = qemu_get_byte(f); - qemu_get_buffer(f, (uint8_t *)idstr, len); - idstr[len] = 0; + if (qemu_get_counted_string(f, idstr)) { + error_report("Unable to read ID string for section %u", + section_id); + return -EINVAL; + } instance_id = qemu_get_be32(f); version_id = qemu_get_be32(f); -- 2.1.0