On Sat 07-07-18 13:36:21, Eric Biggers wrote: > From: Eric Biggers <[email protected]> > > ReiserFS prepares log messages into a 1024-byte buffer with no bounds > checks. Long messages, such as the "unknown mount option" warning when > userspace passes a crafted mount options string, overflow this buffer. > This causes KASAN to report a global-out-of-bounds write. > > Fix it by truncating messages to the buffer size. > > Reported-by: [email protected] > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Signed-off-by: Eric Biggers <[email protected]>
Looks good to me. You can add: Reviewed-by: Jan Kara <[email protected]> I'd just note that I'd prefer some lines not to exceed 80 chars like: - sprintf_le_key(p, va_arg(args, struct reiserfs_key *)); + p += scnprintf_le_key(p, end - p, + va_arg(args, struct reiserfs_key *)); could be: + p += scnprintf_le_key(p, end - p, + va_arg(args, struct reiserfs_key *)); But I don't mind that much. Andrew usually merges reiserfs patches. Andrew? Honza > --- > fs/reiserfs/prints.c | 141 +++++++++++++++++++++++++------------------ > 1 file changed, 81 insertions(+), 60 deletions(-) > > diff --git a/fs/reiserfs/prints.c b/fs/reiserfs/prints.c > index 7e288d97adcbb..9fed1c05f1f4d 100644 > --- a/fs/reiserfs/prints.c > +++ b/fs/reiserfs/prints.c > @@ -76,83 +76,99 @@ static char *le_type(struct reiserfs_key *key) > } > > /* %k */ > -static void sprintf_le_key(char *buf, struct reiserfs_key *key) > +static int scnprintf_le_key(char *buf, size_t size, struct reiserfs_key *key) > { > if (key) > - sprintf(buf, "[%d %d %s %s]", le32_to_cpu(key->k_dir_id), > - le32_to_cpu(key->k_objectid), le_offset(key), > - le_type(key)); > + return scnprintf(buf, size, "[%d %d %s %s]", > + le32_to_cpu(key->k_dir_id), > + le32_to_cpu(key->k_objectid), le_offset(key), > + le_type(key)); > else > - sprintf(buf, "[NULL]"); > + return scnprintf(buf, size, "[NULL]"); > } > > /* %K */ > -static void sprintf_cpu_key(char *buf, struct cpu_key *key) > +static int scnprintf_cpu_key(char *buf, size_t size, struct cpu_key *key) > { > if (key) > - sprintf(buf, "[%d %d %s %s]", key->on_disk_key.k_dir_id, > - key->on_disk_key.k_objectid, reiserfs_cpu_offset(key), > - cpu_type(key)); > + return scnprintf(buf, size, "[%d %d %s %s]", > + key->on_disk_key.k_dir_id, > + key->on_disk_key.k_objectid, > + reiserfs_cpu_offset(key), cpu_type(key)); > else > - sprintf(buf, "[NULL]"); > + return scnprintf(buf, size, "[NULL]"); > } > > -static void sprintf_de_head(char *buf, struct reiserfs_de_head *deh) > +static int scnprintf_de_head(char *buf, size_t size, > + struct reiserfs_de_head *deh) > { > if (deh) > - sprintf(buf, > - "[offset=%d dir_id=%d objectid=%d location=%d > state=%04x]", > - deh_offset(deh), deh_dir_id(deh), deh_objectid(deh), > - deh_location(deh), deh_state(deh)); > + return scnprintf(buf, size, > + "[offset=%d dir_id=%d objectid=%d location=%d > state=%04x]", > + deh_offset(deh), deh_dir_id(deh), > + deh_objectid(deh), deh_location(deh), > + deh_state(deh)); > else > - sprintf(buf, "[NULL]"); > + return scnprintf(buf, size, "[NULL]"); > > } > > -static void sprintf_item_head(char *buf, struct item_head *ih) > +static int scnprintf_item_head(char *buf, size_t size, struct item_head *ih) > { > if (ih) { > - strcpy(buf, > - (ih_version(ih) == KEY_FORMAT_3_6) ? "*3.6* " : "*3.5*"); > - sprintf_le_key(buf + strlen(buf), &(ih->ih_key)); > - sprintf(buf + strlen(buf), ", item_len %d, item_location %d, " > - "free_space(entry_count) %d", > - ih_item_len(ih), ih_location(ih), ih_free_space(ih)); > + char *p = buf; > + char * const end = buf + size; > + > + p += scnprintf(p, end - p, "%s", > + (ih_version(ih) == KEY_FORMAT_3_6) ? > + "*3.6* " : "*3.5*"); > + > + p += scnprintf_le_key(p, end - p, &ih->ih_key); > + > + p += scnprintf(p, end - p, > + ", item_len %d, item_location %d, > free_space(entry_count) %d", > + ih_item_len(ih), ih_location(ih), > + ih_free_space(ih)); > + return p - buf; > } else > - sprintf(buf, "[NULL]"); > + return scnprintf(buf, size, "[NULL]"); > } > > -static void sprintf_direntry(char *buf, struct reiserfs_dir_entry *de) > +static int scnprintf_direntry(char *buf, size_t size, > + struct reiserfs_dir_entry *de) > { > char name[20]; > > memcpy(name, de->de_name, de->de_namelen > 19 ? 19 : de->de_namelen); > name[de->de_namelen > 19 ? 19 : de->de_namelen] = 0; > - sprintf(buf, "\"%s\"==>[%d %d]", name, de->de_dir_id, de->de_objectid); > + return scnprintf(buf, size, "\"%s\"==>[%d %d]", > + name, de->de_dir_id, de->de_objectid); > } > > -static void sprintf_block_head(char *buf, struct buffer_head *bh) > +static int scnprintf_block_head(char *buf, size_t size, struct buffer_head > *bh) > { > - sprintf(buf, "level=%d, nr_items=%d, free_space=%d rdkey ", > - B_LEVEL(bh), B_NR_ITEMS(bh), B_FREE_SPACE(bh)); > + return scnprintf(buf, size, > + "level=%d, nr_items=%d, free_space=%d rdkey ", > + B_LEVEL(bh), B_NR_ITEMS(bh), B_FREE_SPACE(bh)); > } > > -static void sprintf_buffer_head(char *buf, struct buffer_head *bh) > +static int scnprintf_buffer_head(char *buf, size_t size, struct buffer_head > *bh) > { > - sprintf(buf, > - "dev %pg, size %zd, blocknr %llu, count %d, state 0x%lx, page > %p, (%s, %s, %s)", > - bh->b_bdev, bh->b_size, > - (unsigned long long)bh->b_blocknr, atomic_read(&(bh->b_count)), > - bh->b_state, bh->b_page, > - buffer_uptodate(bh) ? "UPTODATE" : "!UPTODATE", > - buffer_dirty(bh) ? "DIRTY" : "CLEAN", > - buffer_locked(bh) ? "LOCKED" : "UNLOCKED"); > + return scnprintf(buf, size, > + "dev %pg, size %zd, blocknr %llu, count %d, state > 0x%lx, page %p, (%s, %s, %s)", > + bh->b_bdev, bh->b_size, > + (unsigned long long)bh->b_blocknr, > + atomic_read(&(bh->b_count)), > + bh->b_state, bh->b_page, > + buffer_uptodate(bh) ? "UPTODATE" : "!UPTODATE", > + buffer_dirty(bh) ? "DIRTY" : "CLEAN", > + buffer_locked(bh) ? "LOCKED" : "UNLOCKED"); > } > > -static void sprintf_disk_child(char *buf, struct disk_child *dc) > +static int scnprintf_disk_child(char *buf, size_t size, struct disk_child > *dc) > { > - sprintf(buf, "[dc_number=%d, dc_size=%u]", dc_block_number(dc), > - dc_size(dc)); > + return scnprintf(buf, size, "[dc_number=%d, dc_size=%u]", > + dc_block_number(dc), dc_size(dc)); > } > > static char *is_there_reiserfs_struct(char *fmt, int *what) > @@ -189,55 +205,60 @@ static void prepare_error_buf(const char *fmt, va_list > args) > char *fmt1 = fmt_buf; > char *k; > char *p = error_buf; > + char * const end = &error_buf[sizeof(error_buf)]; > int what; > > spin_lock(&error_lock); > > - strcpy(fmt1, fmt); > + if (WARN_ON(strscpy(fmt_buf, fmt, sizeof(fmt_buf)) < 0)) { > + strscpy(error_buf, "format string too long", end - error_buf); > + goto out_unlock; > + } > > while ((k = is_there_reiserfs_struct(fmt1, &what)) != NULL) { > *k = 0; > > - p += vsprintf(p, fmt1, args); > + p += vscnprintf(p, end - p, fmt1, args); > > switch (what) { > case 'k': > - sprintf_le_key(p, va_arg(args, struct reiserfs_key *)); > + p += scnprintf_le_key(p, end - p, > + va_arg(args, struct reiserfs_key > *)); > break; > case 'K': > - sprintf_cpu_key(p, va_arg(args, struct cpu_key *)); > + p += scnprintf_cpu_key(p, end - p, > + va_arg(args, struct cpu_key *)); > break; > case 'h': > - sprintf_item_head(p, va_arg(args, struct item_head *)); > + p += scnprintf_item_head(p, end - p, > + va_arg(args, struct item_head > *)); > break; > case 't': > - sprintf_direntry(p, > - va_arg(args, > - struct reiserfs_dir_entry *)); > + p += scnprintf_direntry(p, end - p, > + va_arg(args, struct > reiserfs_dir_entry *)); > break; > case 'y': > - sprintf_disk_child(p, > - va_arg(args, struct disk_child *)); > + p += scnprintf_disk_child(p, end - p, > + va_arg(args, struct > disk_child *)); > break; > case 'z': > - sprintf_block_head(p, > - va_arg(args, struct buffer_head *)); > + p += scnprintf_block_head(p, end - p, > + va_arg(args, struct > buffer_head *)); > break; > case 'b': > - sprintf_buffer_head(p, > - va_arg(args, struct buffer_head *)); > + p += scnprintf_buffer_head(p, end - p, > + va_arg(args, struct > buffer_head *)); > break; > case 'a': > - sprintf_de_head(p, > - va_arg(args, > - struct reiserfs_de_head *)); > + p += scnprintf_de_head(p, end - p, > + va_arg(args, struct > reiserfs_de_head *)); > break; > } > > - p += strlen(p); > fmt1 = k + 2; > } > - vsprintf(p, fmt1, args); > + p += vscnprintf(p, end - p, fmt1, args); > +out_unlock: > spin_unlock(&error_lock); > > } > -- > 2.18.0 > > -- Jan Kara <[email protected]> SUSE Labs, CR
