From b534e70cf5529378a1ed994492641ec0330554eb Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Sat, 13 Oct 2007 11:35:58 +0100 Subject: [JFFS2] Handle dirents on the flash with embedded zero bytes in names. In three places: summary scan, normal scan, REF_PRISTINE GC. Just truncate at the NUL, since that was the correct thing to do in the only case where this (inexplicable) breakage has been seen. Signed-off-by: David Woodhouse --- fs/jffs2/gc.c | 7 ++++++- fs/jffs2/scan.c | 15 +++++++++++---- fs/jffs2/summary.c | 22 ++++++++++++++++++---- 3 files changed, 35 insertions(+), 9 deletions(-) diff --git a/fs/jffs2/gc.c b/fs/jffs2/gc.c index 95be264fe9b6..f25e485ed879 100644 --- a/fs/jffs2/gc.c +++ b/fs/jffs2/gc.c @@ -608,10 +608,15 @@ static int jffs2_garbage_collect_pristine(struct jffs2_sb_info *c, goto bail; } + if (strnlen(node->d.name, node->d.nsize) != node->d.nsize) { + printk(KERN_WARNING "Name in dirent node at 0x%08x contains zeroes\n", ref_offset(raw)); + goto bail; + } + if (node->d.nsize) { crc = crc32(0, node->d.name, node->d.nsize); if (je32_to_cpu(node->d.name_crc) != crc) { - printk(KERN_WARNING "Name CRC failed on REF_PRISTINE dirent ode at 0x%08x: Read 0x%08x, calculated 0x%08x\n", + printk(KERN_WARNING "Name CRC failed on REF_PRISTINE dirent node at 0x%08x: Read 0x%08x, calculated 0x%08x\n", ref_offset(raw), je32_to_cpu(node->d.name_crc), crc); goto bail; } diff --git a/fs/jffs2/scan.c b/fs/jffs2/scan.c index 35ef8d83366f..272872d27fd5 100644 --- a/fs/jffs2/scan.c +++ b/fs/jffs2/scan.c @@ -1004,6 +1004,7 @@ static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblo { struct jffs2_full_dirent *fd; struct jffs2_inode_cache *ic; + uint32_t checkedlen; uint32_t crc; int err; @@ -1024,12 +1025,18 @@ static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblo pseudo_random += je32_to_cpu(rd->version); - fd = jffs2_alloc_full_dirent(rd->nsize+1); + /* Should never happen. Did. (OLPC trac #4184)*/ + checkedlen = strnlen(rd->name, rd->nsize); + if (checkedlen < rd->nsize) { + printk(KERN_ERR "Dirent at %08x has zeroes in name. Truncating to %d chars\n", + ofs, checkedlen); + } + fd = jffs2_alloc_full_dirent(checkedlen+1); if (!fd) { return -ENOMEM; } - memcpy(&fd->name, rd->name, rd->nsize); - fd->name[rd->nsize] = 0; + memcpy(&fd->name, rd->name, checkedlen); + fd->name[checkedlen] = 0; crc = crc32(0, fd->name, rd->nsize); if (crc != je32_to_cpu(rd->name_crc)) { @@ -1055,7 +1062,7 @@ static int jffs2_scan_dirent_node(struct jffs2_sb_info *c, struct jffs2_eraseblo fd->next = NULL; fd->version = je32_to_cpu(rd->version); fd->ino = je32_to_cpu(rd->ino); - fd->nhash = full_name_hash(fd->name, rd->nsize); + fd->nhash = full_name_hash(fd->name, checkedlen); fd->type = rd->type; jffs2_add_fd_to_list(c, fd, &ic->scan_dents); diff --git a/fs/jffs2/summary.c b/fs/jffs2/summary.c index 2a77d3f93029..629af01e5ade 100644 --- a/fs/jffs2/summary.c +++ b/fs/jffs2/summary.c @@ -429,6 +429,7 @@ static int jffs2_sum_process_sum_data(struct jffs2_sb_info *c, struct jffs2_eras case JFFS2_NODETYPE_DIRENT: { struct jffs2_sum_dirent_flash *spd; + int checkedlen; spd = sp; dbg_summary("Dirent at 0x%08x-0x%08x\n", @@ -436,12 +437,25 @@ static int jffs2_sum_process_sum_data(struct jffs2_sb_info *c, struct jffs2_eras jeb->offset + je32_to_cpu(spd->offset) + je32_to_cpu(spd->totlen)); - fd = jffs2_alloc_full_dirent(spd->nsize+1); + /* This should never happen, but https://dev.laptop.org/ticket/4184 */ + checkedlen = strnlen(spd->name, spd->nsize); + if (!checkedlen) { + printk(KERN_ERR "Dirent at %08x has zero at start of name. Aborting mount.\n", + jeb->offset + je32_to_cpu(spd->offset)); + return -EIO; + } + if (checkedlen < spd->nsize) { + printk(KERN_ERR "Dirent at %08x has zeroes in name. Truncating to %d chars\n", + jeb->offset + je32_to_cpu(spd->offset), checkedlen); + } + + + fd = jffs2_alloc_full_dirent(checkedlen+1); if (!fd) return -ENOMEM; - memcpy(&fd->name, spd->name, spd->nsize); - fd->name[spd->nsize] = 0; + memcpy(&fd->name, spd->name, checkedlen); + fd->name[checkedlen] = 0; ic = jffs2_scan_make_ino_cache(c, je32_to_cpu(spd->pino)); if (!ic) { @@ -455,7 +469,7 @@ static int jffs2_sum_process_sum_data(struct jffs2_sb_info *c, struct jffs2_eras fd->next = NULL; fd->version = je32_to_cpu(spd->version); fd->ino = je32_to_cpu(spd->ino); - fd->nhash = full_name_hash(fd->name, spd->nsize); + fd->nhash = full_name_hash(fd->name, checkedlen); fd->type = spd->type; jffs2_add_fd_to_list(c, fd, &ic->scan_dents); -- cgit v1.2.1