Hi Allan,
Le 23/05/2026 à 16:48, Allan ELKAIM a écrit :
sqfs_find_inode() returns NULL on failure, and sqfs_dir_offset()
returns -EINVAL on failure. At 8 call sites in sqfs.c neither return
value was validated before the result was cast to a struct pointer or
used as an array index.
On squashfs images with large inode/directory tables (e.g. containing
the tzdata timezone database), sqfs_dir_offset() fails to locate a
start_block in the metadata-block position list and returns -EINVAL.
The caller then computes &dir_table[-22], producing a faulting address
of 0xffffffffffffffea and a Synchronous Abort on ARM64:
"Synchronous Abort" handler, esr 0x96000004, far 0xffffffffffffffea
The "Error: invalid inode reference to directory table." message
printed just before the abort confirms the sqfs_dir_offset() path.
Additionally, sqfs_find_inode() can return NULL when the inode table
scan encounters an unknown or malformed inode type, after which any
dereference of the cast pointer crashes.
Add NULL guards after every sqfs_find_inode() call and negative-value
guards after every sqfs_dir_offset() call so that any lookup failure
propagates as -EINVAL rather than crashing.
Signed-off-by: Allan Elkaim <[email protected]>
Actually, when sending a v2, you should re-send the whole series (patches
0/2, 1/2, 2/2), as a new thread (not replying to v1).
Then, in cover letter (v0), you should describe the changes from v1 to v2
ex:
https://lore.kernel.org/u-boot/[email protected]/T/
(example taken randomly)
(here, it would be
The subject should remain the same so that we don't get lost.
Also, it's nice to use --base argument on git format-patch so that we know
which commit this series is based on.
On a v2, you are also expected to gather the Reviewed-by/Acked-by (here,
it would be my reviewed-by on patch 1/2, and Miquel's Acked-by on both patches)
Some documentation about that:
https://elixir.bootlin.com/u-boot/v2026.07-rc2/source/doc/develop/sending_patches.rst
---
fs/squashfs/sqfs.c | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/fs/squashfs/sqfs.c b/fs/squashfs/sqfs.c
index 1430e671..da8fbb5a 100644
--- a/fs/squashfs/sqfs.c
+++ b/fs/squashfs/sqfs.c
@@ -472,12 +472,16 @@ static int sqfs_search_dir(struct squashfs_dir_stream
*dirs, char **token_list,
/* Start by root inode */
table = sqfs_find_inode(dirs->inode_table, le32_to_cpu(sblk->inodes),
sblk->inodes, sblk->block_size);
+ if (!table)
+ return -EINVAL;
This is weird since this check is already in uboot tree, so this patch
doesn't apply.
(it was introduced by: 3fb1df1e57ee ("squashfs: Check sqfs_find_inode() return
value"))
Please resent a v3 (whole series), with changes described and the commit
it's based on. (v2026.07-rc3 for example)
Thanks!
Regards,
Richard
dir = (struct squashfs_dir_inode *)table;
ldir = (struct squashfs_ldir_inode *)table;
/* get directory offset in directory table */
offset = sqfs_dir_offset(table, m_list, m_count);
+ if (offset < 0)
+ return offset;
dirs->table = &dirs->dir_table[offset];
/* Setup directory header */
@@ -527,6 +531,12 @@ static int sqfs_search_dir(struct squashfs_dir_stream
*dirs, char **token_list,
/* Get reference to inode in the inode table */
table = sqfs_find_inode(dirs->inode_table, new_inode_number,
sblk->inodes, sblk->block_size);
+ if (!table) {
+ free(dirs->entry);
+ dirs->entry = NULL;
+ ret = -EINVAL;
+ goto out;
+ }
dir = (struct squashfs_dir_inode *)table;
/* Check for symbolic link and inode type sanity */
@@ -599,6 +609,12 @@ static int sqfs_search_dir(struct squashfs_dir_stream
*dirs, char **token_list,
/* Get dir. offset into the directory table */
offset = sqfs_dir_offset(table, m_list, m_count);
+ if (offset < 0) {
+ free(dirs->entry);
+ dirs->entry = NULL;
+ ret = offset;
+ goto out;
+ }
dirs->table = &dirs->dir_table[offset];
/* Copy directory header */
@@ -623,6 +639,12 @@ static int sqfs_search_dir(struct squashfs_dir_stream
*dirs, char **token_list,
}
offset = sqfs_dir_offset(table, m_list, m_count);
+ if (offset < 0) {
+ free(dirs->entry);
+ dirs->entry = NULL;
+ ret = offset;
+ goto out;
+ }
dirs->table = &dirs->dir_table[offset];
if (get_unaligned_le16(&dir->inode_type) == SQFS_DIR_TYPE)
@@ -1023,6 +1045,8 @@ int sqfs_readdir(struct fs_dir_stream *fs_dirs, struct
fs_dirent **dentp)
i_number = dirs->dir_header->inode_number + dirs->entry->inode_offset;
ipos = sqfs_find_inode(dirs->inode_table, i_number, sblk->inodes,
sblk->block_size);
+ if (!ipos)
+ return -SQFS_STOP_READDIR;
base = (struct squashfs_base_inode *)ipos;
@@ -1379,6 +1403,10 @@ int sqfs_read(const char *filename, void *buf, loff_t offset, loff_t len,
i_number = dirs->dir_header->inode_number + dirs->entry->inode_offset;
ipos = sqfs_find_inode(dirs->inode_table, i_number, sblk->inodes,
sblk->block_size);
+ if (!ipos) {
+ ret = -EINVAL;
+ goto out;
+ }
base = (struct squashfs_base_inode *)ipos;
switch (get_unaligned_le16(&base->inode_type)) {
@@ -1629,6 +1657,11 @@ int sqfs_size(const char *filename, loff_t *size)
sblk->block_size);
free(dirs->entry);
dirs->entry = NULL;
+ if (!ipos) {
+ *size = 0;
+ ret = -EINVAL;
+ goto free_strings;
+ }
base = (struct squashfs_base_inode *)ipos;
switch (get_unaligned_le16(&base->inode_type)) {
--
Richard Genoud, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
