unimore/kernel-hacking-2024-linux-steffo
unimore/kernel-hacking-2024-linux-steffo
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[JFFS2] Handle dirents on the flash with embedded zero bytes in names.

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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 <dwmw2@infradead.org>
This commit is contained in:
David Woodhouse 2007-10-13 11:35:58 +01:00
parent 69ca4378aa
commit b534e70cf5
3 changed files with 35 additions and 9 deletions
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7
fs/jffs2/gc.c
View file

@ -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;
}

15
fs/jffs2/scan.c
View file

@ -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);

22
fs/jffs2/summary.c
View file

@ -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);