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- From 3334a5e6c86f10e715cca3bf66ce0fc2f164b61b Mon Sep 17 00:00:00 2001
- From: Daniel Axtens <dja@axtens.net>
- Date: Wed, 13 Jan 2021 20:59:09 +1100
- Subject: [PATCH] io/gzio: Bail if gzio->tl/td is NULL
- This is an ugly fix that doesn't address why gzio->tl comes to be NULL.
- However, it seems to be sufficient to patch up a bunch of NULL derefs.
- It would be good to revisit this in future and see if we can have
- a cleaner solution that addresses some of the causes of the unexpected
- NULL pointers.
- Signed-off-by: Daniel Axtens <dja@axtens.net>
- Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
- Signed-off-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
- ---
- grub-core/io/gzio.c | 20 ++++++++++++++++++++
- 1 file changed, 20 insertions(+)
- diff --git a/grub-core/io/gzio.c b/grub-core/io/gzio.c
- index 43d98a7..4a8eaea 100644
- --- a/grub-core/io/gzio.c
- +++ b/grub-core/io/gzio.c
- @@ -669,6 +669,13 @@ inflate_codes_in_window (grub_gzio_t gzio)
- {
- if (! gzio->code_state)
- {
- +
- + if (gzio->tl == NULL)
- + {
- + grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, "NULL gzio->tl");
- + return 1;
- + }
- +
- NEEDBITS ((unsigned) gzio->bl);
- if ((e = (t = gzio->tl + ((unsigned) b & ml))->e) > 16)
- do
- @@ -707,6 +714,12 @@ inflate_codes_in_window (grub_gzio_t gzio)
- n = t->v.n + ((unsigned) b & mask_bits[e]);
- DUMPBITS (e);
-
- + if (gzio->td == NULL)
- + {
- + grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, "NULL gzio->td");
- + return 1;
- + }
- +
- /* decode distance of block to copy */
- NEEDBITS ((unsigned) gzio->bd);
- if ((e = (t = gzio->td + ((unsigned) b & md))->e) > 16)
- @@ -917,6 +930,13 @@ init_dynamic_block (grub_gzio_t gzio)
- n = nl + nd;
- m = mask_bits[gzio->bl];
- i = l = 0;
- +
- + if (gzio->tl == NULL)
- + {
- + grub_error (GRUB_ERR_BAD_COMPRESSED_DATA, "NULL gzio->tl");
- + return;
- + }
- +
- while ((unsigned) i < n)
- {
- NEEDBITS ((unsigned) gzio->bl);
- --
- 2.14.2
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