From 3877f0b6c9f54d43e55e532404a935b90393b635 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Sun, 18 Jun 2006 00:05:26 +0100 Subject: [PATCH] [JFFS2] Don't trust node headers before the CRC is checked. Especially when summary code is used, we can have in-memory data structures referencing certain nodes without them actually being readable on the flash. Discard the nodes gracefully in that case, rather than triggering a BUG(). Signed-off-by: David Woodhouse --- fs/jffs2/readinode.c | 62 ++++++++++++++++++++++++++++------------------------ 1 file changed, 34 insertions(+), 28 deletions(-) diff --git a/fs/jffs2/readinode.c b/fs/jffs2/readinode.c index e1acce8..5351b34 100644 --- a/fs/jffs2/readinode.c +++ b/fs/jffs2/readinode.c @@ -343,7 +343,7 @@ free_out: * Helper function for jffs2_get_inode_nodes(). * It is called every time an unknown node is found. * - * Returns: 0 on succes; + * Returns: 0 on success; * 1 if the node should be marked obsolete; * negative error code on failure. */ @@ -354,37 +354,30 @@ static inline int read_unknown(struct jffs2_sb_info *c, struct jffs2_raw_node_re un->nodetype = cpu_to_je16(JFFS2_NODE_ACCURATE | je16_to_cpu(un->nodetype)); - if (crc32(0, un, sizeof(struct jffs2_unknown_node) - 4) != je32_to_cpu(un->hdr_crc)) { - /* Hmmm. This should have been caught at scan time. */ - JFFS2_NOTICE("node header CRC failed at %#08x. But it must have been OK earlier.\n", ref_offset(ref)); - jffs2_dbg_dump_node(c, ref_offset(ref)); - return 1; - } else { - switch(je16_to_cpu(un->nodetype) & JFFS2_COMPAT_MASK) { + switch(je16_to_cpu(un->nodetype) & JFFS2_COMPAT_MASK) { - case JFFS2_FEATURE_INCOMPAT: - JFFS2_ERROR("unknown INCOMPAT nodetype %#04X at %#08x\n", - je16_to_cpu(un->nodetype), ref_offset(ref)); - /* EEP */ - BUG(); - break; + case JFFS2_FEATURE_INCOMPAT: + JFFS2_ERROR("unknown INCOMPAT nodetype %#04X at %#08x\n", + je16_to_cpu(un->nodetype), ref_offset(ref)); + /* EEP */ + BUG(); + break; - case JFFS2_FEATURE_ROCOMPAT: - JFFS2_ERROR("unknown ROCOMPAT nodetype %#04X at %#08x\n", - je16_to_cpu(un->nodetype), ref_offset(ref)); - BUG_ON(!(c->flags & JFFS2_SB_FLAG_RO)); - break; + case JFFS2_FEATURE_ROCOMPAT: + JFFS2_ERROR("unknown ROCOMPAT nodetype %#04X at %#08x\n", + je16_to_cpu(un->nodetype), ref_offset(ref)); + BUG_ON(!(c->flags & JFFS2_SB_FLAG_RO)); + break; - case JFFS2_FEATURE_RWCOMPAT_COPY: - JFFS2_NOTICE("unknown RWCOMPAT_COPY nodetype %#04X at %#08x\n", - je16_to_cpu(un->nodetype), ref_offset(ref)); - break; + case JFFS2_FEATURE_RWCOMPAT_COPY: + JFFS2_NOTICE("unknown RWCOMPAT_COPY nodetype %#04X at %#08x\n", + je16_to_cpu(un->nodetype), ref_offset(ref)); + break; - case JFFS2_FEATURE_RWCOMPAT_DELETE: - JFFS2_NOTICE("unknown RWCOMPAT_DELETE nodetype %#04X at %#08x\n", - je16_to_cpu(un->nodetype), ref_offset(ref)); - return 1; - } + case JFFS2_FEATURE_RWCOMPAT_DELETE: + JFFS2_NOTICE("unknown RWCOMPAT_DELETE nodetype %#04X at %#08x\n", + je16_to_cpu(un->nodetype), ref_offset(ref)); + return 1; } return 0; @@ -549,6 +542,18 @@ static int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_inf node = (union jffs2_node_union *)bufstart; + /* No need to mask in the valid bit; it shouldn't be invalid */ + if (je32_to_cpu(node->u.hdr_crc) != crc32(0, node, sizeof(node->u)-4)) { + JFFS2_NOTICE("Node header CRC failed at %#08x. {%04x,%04x,%08x,%08x}\n", + ref_offset(ref), je16_to_cpu(node->u.magic), + je16_to_cpu(node->u.nodetype), + je32_to_cpu(node->u.totlen), + je32_to_cpu(node->u.hdr_crc)); + jffs2_dbg_dump_node(c, ref_offset(ref)); + jffs2_mark_node_obsolete(c, ref); + goto cont; + } + switch (je16_to_cpu(node->u.nodetype)) { case JFFS2_NODETYPE_DIRENT: @@ -606,6 +611,7 @@ static int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_inf goto free_out; } + cont: spin_lock(&c->erase_completion_lock); } -- 2.7.4