Various fixes and tweaks for the pstore subsystem. Highlights:

- use memdup_user() instead of open-coded copies (Geliang Tang)
 - fix record memory leak during initialization (Douglas Anderson)
 - avoid confused compressed record warning (Ankit Kumar)
 - prepopulate record timestamp and remove redundant logic from backends
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 Comment: Kees Cook <kees@outflux.net>
 
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 nGysSHuEQmDMSmTpXKllmi+AVotMXtvLzeEy0ThmtaTYJPUF2NYi4BIv0SonAu/v
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Merge tag 'pstore-v4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull pstore updates from Kees Cook:
 "Various fixes and tweaks for the pstore subsystem.

  Highlights:

   - use memdup_user() instead of open-coded copies (Geliang Tang)

   - fix record memory leak during initialization (Douglas Anderson)

   - avoid confused compressed record warning (Ankit Kumar)

   - prepopulate record timestamp and remove redundant logic from
     backends"

* tag 'pstore-v4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  powerpc/nvram: use memdup_user
  pstore: use memdup_user
  pstore: Fix format string to use %u for record id
  pstore: Populate pstore record->time field
  pstore: Create common record initializer
  efi-pstore: Refactor erase routine
  pstore: Avoid potential infinite loop
  pstore: Fix leaked pstore_record in pstore_get_backend_records()
  pstore: Don't warn if data is uncompressed and type is not PSTORE_TYPE_DMESG
This commit is contained in:
Linus Torvalds 2017-07-05 11:43:47 -07:00
commit 2cc7b4ca7d
8 changed files with 116 additions and 113 deletions

View File

@ -792,21 +792,17 @@ static ssize_t dev_nvram_write(struct file *file, const char __user *buf,
count = min_t(size_t, count, size - *ppos);
count = min(count, PAGE_SIZE);
ret = -ENOMEM;
tmp = kmalloc(count, GFP_KERNEL);
if (!tmp)
goto out;
ret = -EFAULT;
if (copy_from_user(tmp, buf, count))
tmp = memdup_user(buf, count);
if (IS_ERR(tmp)) {
ret = PTR_ERR(tmp);
goto out;
}
ret = ppc_md.nvram_write(tmp, count, ppos);
out:
kfree(tmp);
out:
return ret;
}
static long dev_nvram_ioctl(struct file *file, unsigned int cmd,

View File

@ -4,7 +4,7 @@
#include <linux/slab.h>
#include <linux/ucs2_string.h>
#define DUMP_NAME_LEN 52
#define DUMP_NAME_LEN 66
static bool efivars_pstore_disable =
IS_ENABLED(CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE);
@ -244,12 +244,12 @@ static int efi_pstore_write(struct pstore_record *record)
efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
int i, ret = 0;
record->time.tv_sec = get_seconds();
record->time.tv_nsec = 0;
record->id = generic_id(record->time.tv_sec, record->part,
record->count);
/* Since we copy the entire length of name, make sure it is wiped. */
memset(name, 0, sizeof(name));
snprintf(name, sizeof(name), "dump-type%u-%u-%d-%lu-%c",
record->type, record->part, record->count,
record->time.tv_sec, record->compressed ? 'C' : 'D');
@ -267,44 +267,20 @@ static int efi_pstore_write(struct pstore_record *record)
return ret;
};
struct pstore_erase_data {
struct pstore_record *record;
efi_char16_t *name;
};
/*
* Clean up an entry with the same name
*/
static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
{
struct pstore_erase_data *ed = data;
efi_char16_t *efi_name = data;
efi_guid_t vendor = LINUX_EFI_CRASH_GUID;
efi_char16_t efi_name_old[DUMP_NAME_LEN];
efi_char16_t *efi_name = ed->name;
unsigned long ucs2_len = ucs2_strlen(ed->name);
char name_old[DUMP_NAME_LEN];
int i;
unsigned long ucs2_len = ucs2_strlen(efi_name);
if (efi_guidcmp(entry->var.VendorGuid, vendor))
return 0;
if (ucs2_strncmp(entry->var.VariableName,
efi_name, (size_t)ucs2_len)) {
/*
* Check if an old format, which doesn't support
* holding multiple logs, remains.
*/
snprintf(name_old, sizeof(name_old), "dump-type%u-%u-%lu",
ed->record->type, ed->record->part,
ed->record->time.tv_sec);
for (i = 0; i < DUMP_NAME_LEN; i++)
efi_name_old[i] = name_old[i];
if (ucs2_strncmp(entry->var.VariableName, efi_name_old,
ucs2_strlen(efi_name_old)))
return 0;
}
if (ucs2_strncmp(entry->var.VariableName, efi_name, (size_t)ucs2_len))
return 0;
if (entry->scanning) {
/*
@ -321,35 +297,48 @@ static int efi_pstore_erase_func(struct efivar_entry *entry, void *data)
return 1;
}
static int efi_pstore_erase(struct pstore_record *record)
static int efi_pstore_erase_name(const char *name)
{
struct pstore_erase_data edata;
struct efivar_entry *entry = NULL;
char name[DUMP_NAME_LEN];
efi_char16_t efi_name[DUMP_NAME_LEN];
int found, i;
for (i = 0; i < DUMP_NAME_LEN; i++) {
efi_name[i] = name[i];
if (name[i] == '\0')
break;
}
if (efivar_entry_iter_begin())
return -EINTR;
found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list,
efi_name, &entry);
efivar_entry_iter_end();
if (found && !entry->scanning)
efivar_unregister(entry);
return found ? 0 : -ENOENT;
}
static int efi_pstore_erase(struct pstore_record *record)
{
char name[DUMP_NAME_LEN];
int ret;
snprintf(name, sizeof(name), "dump-type%u-%u-%d-%lu",
record->type, record->part, record->count,
record->time.tv_sec);
ret = efi_pstore_erase_name(name);
if (ret != -ENOENT)
return ret;
for (i = 0; i < DUMP_NAME_LEN; i++)
efi_name[i] = name[i];
snprintf(name, sizeof(name), "dump-type%u-%u-%lu",
record->type, record->part, record->time.tv_sec);
ret = efi_pstore_erase_name(name);
edata.record = record;
edata.name = efi_name;
if (efivar_entry_iter_begin())
return -EINTR;
found = __efivar_entry_iter(efi_pstore_erase_func, &efivar_sysfs_list, &edata, &entry);
if (found && !entry->scanning) {
efivar_entry_iter_end();
efivar_unregister(entry);
} else
efivar_entry_iter_end();
return 0;
return ret;
}
static struct pstore_info efi_pstore_info = {

View File

@ -349,48 +349,48 @@ int pstore_mkfile(struct dentry *root, struct pstore_record *record)
switch (record->type) {
case PSTORE_TYPE_DMESG:
scnprintf(name, sizeof(name), "dmesg-%s-%lld%s",
scnprintf(name, sizeof(name), "dmesg-%s-%llu%s",
record->psi->name, record->id,
record->compressed ? ".enc.z" : "");
break;
case PSTORE_TYPE_CONSOLE:
scnprintf(name, sizeof(name), "console-%s-%lld",
scnprintf(name, sizeof(name), "console-%s-%llu",
record->psi->name, record->id);
break;
case PSTORE_TYPE_FTRACE:
scnprintf(name, sizeof(name), "ftrace-%s-%lld",
scnprintf(name, sizeof(name), "ftrace-%s-%llu",
record->psi->name, record->id);
break;
case PSTORE_TYPE_MCE:
scnprintf(name, sizeof(name), "mce-%s-%lld",
scnprintf(name, sizeof(name), "mce-%s-%llu",
record->psi->name, record->id);
break;
case PSTORE_TYPE_PPC_RTAS:
scnprintf(name, sizeof(name), "rtas-%s-%lld",
scnprintf(name, sizeof(name), "rtas-%s-%llu",
record->psi->name, record->id);
break;
case PSTORE_TYPE_PPC_OF:
scnprintf(name, sizeof(name), "powerpc-ofw-%s-%lld",
scnprintf(name, sizeof(name), "powerpc-ofw-%s-%llu",
record->psi->name, record->id);
break;
case PSTORE_TYPE_PPC_COMMON:
scnprintf(name, sizeof(name), "powerpc-common-%s-%lld",
scnprintf(name, sizeof(name), "powerpc-common-%s-%llu",
record->psi->name, record->id);
break;
case PSTORE_TYPE_PMSG:
scnprintf(name, sizeof(name), "pmsg-%s-%lld",
scnprintf(name, sizeof(name), "pmsg-%s-%llu",
record->psi->name, record->id);
break;
case PSTORE_TYPE_PPC_OPAL:
scnprintf(name, sizeof(name), "powerpc-opal-%s-%lld",
scnprintf(name, sizeof(name), "powerpc-opal-%s-%llu",
record->psi->name, record->id);
break;
case PSTORE_TYPE_UNKNOWN:
scnprintf(name, sizeof(name), "unknown-%s-%lld",
scnprintf(name, sizeof(name), "unknown-%s-%llu",
record->psi->name, record->id);
break;
default:
scnprintf(name, sizeof(name), "type%d-%s-%lld",
scnprintf(name, sizeof(name), "type%d-%s-%llu",
record->type, record->psi->name, record->id);
break;
}

View File

@ -30,5 +30,7 @@ extern void pstore_get_backend_records(struct pstore_info *psi,
extern int pstore_mkfile(struct dentry *root,
struct pstore_record *record);
extern bool pstore_is_mounted(void);
extern void pstore_record_init(struct pstore_record *record,
struct pstore_info *psi);
#endif

View File

@ -474,6 +474,20 @@ static size_t copy_kmsg_to_buffer(int hsize, size_t len)
return total_len;
}
void pstore_record_init(struct pstore_record *record,
struct pstore_info *psinfo)
{
memset(record, 0, sizeof(*record));
record->psi = psinfo;
/* Report zeroed timestamp if called before timekeeping has resumed. */
if (__getnstimeofday(&record->time)) {
record->time.tv_sec = 0;
record->time.tv_nsec = 0;
}
}
/*
* callback from kmsg_dump. (s2,l2) has the most recently
* written bytes, older bytes are in (s1,l1). Save as much
@ -509,15 +523,14 @@ static void pstore_dump(struct kmsg_dumper *dumper,
int header_size;
int zipped_len = -1;
size_t dump_size;
struct pstore_record record = {
.type = PSTORE_TYPE_DMESG,
.count = oopscount,
.reason = reason,
.part = part,
.compressed = false,
.buf = psinfo->buf,
.psi = psinfo,
};
struct pstore_record record;
pstore_record_init(&record, psinfo);
record.type = PSTORE_TYPE_DMESG;
record.count = oopscount;
record.reason = reason;
record.part = part;
record.buf = psinfo->buf;
if (big_oops_buf && is_locked) {
dst = big_oops_buf;
@ -587,12 +600,12 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c)
const char *e = s + c;
while (s < e) {
struct pstore_record record = {
.type = PSTORE_TYPE_CONSOLE,
.psi = psinfo,
};
struct pstore_record record;
unsigned long flags;
pstore_record_init(&record, psinfo);
record.type = PSTORE_TYPE_CONSOLE;
if (c > psinfo->bufsize)
c = psinfo->bufsize;
@ -640,19 +653,16 @@ static int pstore_write_user_compat(struct pstore_record *record,
if (record->buf)
return -EINVAL;
record->buf = kmalloc(record->size, GFP_KERNEL);
if (!record->buf)
return -ENOMEM;
if (unlikely(copy_from_user(record->buf, buf, record->size))) {
ret = -EFAULT;
record->buf = memdup_user(buf, record->size);
if (unlikely(IS_ERR(record->buf))) {
ret = PTR_ERR(record->buf);
goto out;
}
ret = record->psi->write(record);
out:
kfree(record->buf);
out:
record->buf = NULL;
return unlikely(ret < 0) ? ret : record->size;
@ -770,8 +780,11 @@ static void decompress_record(struct pstore_record *record)
int unzipped_len;
char *decompressed;
if (!record->compressed)
return;
/* Only PSTORE_TYPE_DMESG support compression. */
if (!record->compressed || record->type != PSTORE_TYPE_DMESG) {
if (record->type != PSTORE_TYPE_DMESG) {
pr_warn("ignored compressed record type %d\n", record->type);
return;
}
@ -819,6 +832,7 @@ void pstore_get_backend_records(struct pstore_info *psi,
struct dentry *root, int quiet)
{
int failed = 0;
unsigned int stop_loop = 65536;
if (!psi || !root)
return;
@ -832,7 +846,7 @@ void pstore_get_backend_records(struct pstore_info *psi,
* may reallocate record.buf. On success, pstore_mkfile() will keep
* the record.buf, so free it only on failure.
*/
for (;;) {
for (; stop_loop; stop_loop--) {
struct pstore_record *record;
int rc;
@ -841,13 +855,15 @@ void pstore_get_backend_records(struct pstore_info *psi,
pr_err("out of memory creating record\n");
break;
}
record->psi = psi;
pstore_record_init(record, psi);
record->size = psi->read(record);
/* No more records left in backend? */
if (record->size <= 0)
if (record->size <= 0) {
kfree(record);
break;
}
decompress_record(record);
rc = pstore_mkfile(root, record);
@ -865,8 +881,11 @@ out:
mutex_unlock(&psi->read_mutex);
if (failed)
pr_warn("failed to load %d record(s) from '%s'\n",
pr_warn("failed to create %d record(s) from '%s'\n",
failed, psi->name);
if (!stop_loop)
pr_err("looping? Too many records seen from '%s'\n",
psi->name);
}
static void pstore_dowork(struct work_struct *work)

View File

@ -22,16 +22,16 @@ static DEFINE_MUTEX(pmsg_lock);
static ssize_t write_pmsg(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct pstore_record record = {
.type = PSTORE_TYPE_PMSG,
.size = count,
.psi = psinfo,
};
struct pstore_record record;
int ret;
if (!count)
return 0;
pstore_record_init(&record, psinfo);
record.type = PSTORE_TYPE_PMSG;
record.size = count;
/* check outside lock, page in any data. write_user also checks */
if (!access_ok(VERIFY_READ, buf, count))
return -EFAULT;

View File

@ -27,7 +27,6 @@
#include <linux/module.h>
#include <linux/version.h>
#include <linux/pstore.h>
#include <linux/time.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/platform_device.h>
@ -356,20 +355,15 @@ out:
}
static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz,
bool compressed)
struct pstore_record *record)
{
char *hdr;
struct timespec timestamp;
size_t len;
/* Report zeroed timestamp if called before timekeeping has resumed. */
if (__getnstimeofday(&timestamp)) {
timestamp.tv_sec = 0;
timestamp.tv_nsec = 0;
}
hdr = kasprintf(GFP_ATOMIC, RAMOOPS_KERNMSG_HDR "%lu.%lu-%c\n",
(long)timestamp.tv_sec, (long)(timestamp.tv_nsec / 1000),
compressed ? 'C' : 'D');
record->time.tv_sec,
record->time.tv_nsec / 1000,
record->compressed ? 'C' : 'D');
WARN_ON_ONCE(!hdr);
len = hdr ? strlen(hdr) : 0;
persistent_ram_write(prz, hdr, len);
@ -440,7 +434,7 @@ static int notrace ramoops_pstore_write(struct pstore_record *record)
prz = cxt->dprzs[cxt->dump_write_cnt];
/* Build header and append record contents. */
hlen = ramoops_write_kmsg_hdr(prz, record->compressed);
hlen = ramoops_write_kmsg_hdr(prz, record);
size = record->size;
if (size + hlen > prz->buffer_size)
size = prz->buffer_size - hlen;

View File

@ -138,7 +138,10 @@ struct pstore_record {
* memory allocation may be broken during an Oops. Regardless,
* @buf must be proccesed or copied before returning. The
* backend is also expected to write @id with something that
8 can help identify this record to a future @erase callback.
* can help identify this record to a future @erase callback.
* The @time field will be prepopulated with the current time,
* when available. The @size field will have the size of data
* in @buf.
*
* Returns 0 on success, and non-zero on error.
*