Currently, the ubifs code allocates a worst case buffer size to recompress a data node, but does not pass the size of that buffer to the compression code. This means that the compression code will never use the additional space, and might fail spuriously due to lack of space. So let's multiply out_len by WORST_COMPR_FACTOR after allocating the buffer. Doing so is guaranteed not to overflow, given that the preceding kmalloc_array() call would have failed otherwise. Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> --- fs/ubifs/journal.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index dc52ac0f4a345f30..4e5961878f336033 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -1493,6 +1493,8 @@ static int truncate_data_node(const struct ubifs_info *c, const struct inode *in if (!buf) return -ENOMEM; + out_len *= WORST_COMPR_FACTOR; + dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ; data_size = dn_size - UBIFS_DATA_NODE_SZ; compr_type = le16_to_cpu(dn->compr_type); -- 2.39.2
