[PATCHv2 3/4] block/sed: Check received header lengths
From: Jon Derrick <hidden>
Date: 2017-02-15 18:13:21
Also in:
linuxppc-dev, lkml
Subsystem:
block layer, secure encrypting device (sed) opal driver, the rest · Maintainers:
Jens Axboe, Jonathan Derrick, Linus Torvalds
Add a buffer size check against discovery and response header lengths before we loop over their buffers. Signed-off-by: Jon Derrick <redacted> --- block/sed-opal.c | 35 +++++++++++++++++++++-------------- 1 file changed, 21 insertions(+), 14 deletions(-)
diff --git a/block/sed-opal.c b/block/sed-opal.c
index d6dd604..addf89e 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c@@ -340,10 +340,17 @@ static int opal_discovery0_end(struct opal_dev *dev) const struct d0_header *hdr = (struct d0_header *)dev->resp; const u8 *epos = dev->resp, *cpos = dev->resp; u16 comid = 0; + u32 hlen = be32_to_cpu(hdr->length); - print_buffer(dev->resp, be32_to_cpu(hdr->length)); + print_buffer(dev->resp, hlen); - epos += be32_to_cpu(hdr->length); /* end of buffer */ + if (hlen > IO_BUFFER_LENGTH - sizeof(*hdr)) { + pr_warn("Discovery length overflows buffer (%zu+%u)/%u\n", + sizeof(*hdr), hlen, IO_BUFFER_LENGTH); + return -EFAULT; + } + + epos += hlen; /* end of buffer */ cpos += sizeof(*hdr); /* current position on buffer */ while (cpos < epos && supported) {
@@ -713,6 +720,7 @@ static int response_parse(const u8 *buf, size_t length, int total; ssize_t token_length; const u8 *pos; + u32 clen, plen, slen; if (!buf) return -EFAULT;
@@ -724,17 +732,16 @@ static int response_parse(const u8 *buf, size_t length, pos = buf; pos += sizeof(*hdr); - pr_debug("Response size: cp: %d, pkt: %d, subpkt: %d\n", - be32_to_cpu(hdr->cp.length), - be32_to_cpu(hdr->pkt.length), - be32_to_cpu(hdr->subpkt.length)); - - if (hdr->cp.length == 0 || hdr->pkt.length == 0 || - hdr->subpkt.length == 0) { - pr_err("Bad header length. cp: %d, pkt: %d, subpkt: %d\n", - be32_to_cpu(hdr->cp.length), - be32_to_cpu(hdr->pkt.length), - be32_to_cpu(hdr->subpkt.length)); + clen = be32_to_cpu(hdr->cp.length); + plen = be32_to_cpu(hdr->pkt.length); + slen = be32_to_cpu(hdr->subpkt.length); + pr_debug("Response size: cp: %u, pkt: %u, subpkt: %u\n", + clen, plen, slen); + + if (clen == 0 || plen == 0 || slen == 0 || + (u64)clen + plen + slen > IO_BUFFER_LENGTH) { + pr_err("Bad header length. cp: %u, pkt: %u, subpkt: %u\n", + clen, plen, slen); print_buffer(pos, sizeof(*hdr)); return -EINVAL; }
@@ -743,7 +750,7 @@ static int response_parse(const u8 *buf, size_t length, return -EFAULT; iter = resp->toks; - total = be32_to_cpu(hdr->subpkt.length); + total = slen; print_buffer(pos, total); while (total > 0) { if (pos[0] <= TINY_ATOM_BYTE) /* tiny atom */
--
1.8.3.1