Eric Lee / smarc-ti-linux-kernel

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Commit e237ec37ec154564f8690c5bd1795339955eeef9

Authored by Jan Kara
1 parent 0e5cc9a40a
Exists in ti-lsk-linux-4.1.y and in 10 other branches dlt-processor-sdk-linux-03.00.00.04, processor-sdk-linux-02.00.01, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04

udf: Check component length before reading it 

Check that length specified in a component of a symlink fits in the
input buffer we are reading. Also properly ignore component length for
component types that do not use it. Otherwise we read memory after end
of buffer for corrupted udf image.

Reported-by: Carl Henrik Lunde <chlunde@ping.uio.no>
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>

Showing 1 changed file with 7 additions and 2 deletions Side-by-side Diff

... ... @@ -42,14 +42,17 @@
42 42 tolen--;
43 43 while (elen < fromlen) {
44 44 pc = (struct pathComponent *)(from + elen);
  45 + elen += sizeof(struct pathComponent);
45 46 switch (pc->componentType) {
46 47 case 1:
47 48 /*
48 49 * Symlink points to some place which should be agreed
49 50 * upon between originator and receiver of the media. Ignore.
50 51 */
51   - if (pc->lengthComponentIdent > 0)
  52 + if (pc->lengthComponentIdent > 0) {
  53 + elen += pc->lengthComponentIdent;
52 54 break;
  55 + }
53 56 /* Fall through */
54 57 case 2:
55 58 if (tolen == 0)
... ... @@ -74,6 +77,9 @@
74 77 /* that would be . - just ignore */
75 78 break;
76 79 case 5:
  80 + elen += pc->lengthComponentIdent;
  81 + if (elen > fromlen)
  82 + return -EIO;
77 83 comp_len = udf_get_filename(sb, pc->componentIdent,
78 84 pc->lengthComponentIdent,
79 85 p, tolen);
... ... @@ -85,7 +91,6 @@
85 91 tolen--;
86 92 break;
87 93 }
88   - elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
89 94 }
90 95 if (p > to + 1)
91 96 p[-1] = '\0';