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| author | Daniel Axtens <dja@axtens.net> | 2020-02-25 10:44:27 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-03-03 08:02:57 +0100 |
| commit | 3745488e9d599916a0b40d45d3f30e3d4720288e (patch) | |
| tree | a761d25cb9e94cc17dcc791414f1c2a8de131796 /drivers/misc/altera-stapl | |
| parent | 2669b8b0c798fbe1a31d49e07aa33233d469ad9b (diff) | |
| download | linux-3745488e9d599916a0b40d45d3f30e3d4720288e.tar.bz2 | |
altera-stapl: altera_get_note: prevent write beyond end of 'key'
altera_get_note is called from altera_init, where key is kzalloc(33).
When the allocation functions are annotated to allow the compiler to see
the sizes of objects, and with FORTIFY_SOURCE, we see:
In file included from drivers/misc/altera-stapl/altera.c:14:0:
In function ‘strlcpy’,
inlined from ‘altera_init’ at drivers/misc/altera-stapl/altera.c:2189:5:
include/linux/string.h:378:4: error: call to ‘__write_overflow’ declared with attribute error: detected write beyond size of object passed as 1st parameter
__write_overflow();
^~~~~~~~~~~~~~~~~~
That refers to this code in altera_get_note:
if (key != NULL)
strlcpy(key, &p[note_strings +
get_unaligned_be32(
&p[note_table + (8 * i)])],
length);
The error triggers because the length of 'key' is 33, but the copy
uses length supplied as the 'length' parameter, which is always
256. Split the size parameter into key_len and val_len, and use the
appropriate length depending on what is being copied.
Detected by compiler error, only compile-tested.
Cc: "Igor M. Liplianin" <liplianin@netup.ru>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Link: https://lore.kernel.org/r/20200120074344.504-2-dja@axtens.net
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/202002251042.D898E67AC@keescook
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/altera-stapl')
| -rw-r--r-- | drivers/misc/altera-stapl/altera.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/drivers/misc/altera-stapl/altera.c b/drivers/misc/altera-stapl/altera.c index 25e5f24b3fec..5bdf57472314 100644 --- a/drivers/misc/altera-stapl/altera.c +++ b/drivers/misc/altera-stapl/altera.c @@ -2112,8 +2112,8 @@ exit_done: return status; } -static int altera_get_note(u8 *p, s32 program_size, - s32 *offset, char *key, char *value, int length) +static int altera_get_note(u8 *p, s32 program_size, s32 *offset, + char *key, char *value, int keylen, int vallen) /* * Gets key and value of NOTE fields in the JBC file. * Can be called in two modes: if offset pointer is NULL, @@ -2170,7 +2170,7 @@ static int altera_get_note(u8 *p, s32 program_size, &p[note_table + (8 * i) + 4])]; if (value != NULL) - strlcpy(value, value_ptr, length); + strlcpy(value, value_ptr, vallen); } } @@ -2189,13 +2189,13 @@ static int altera_get_note(u8 *p, s32 program_size, strlcpy(key, &p[note_strings + get_unaligned_be32( &p[note_table + (8 * i)])], - length); + keylen); if (value != NULL) strlcpy(value, &p[note_strings + get_unaligned_be32( &p[note_table + (8 * i) + 4])], - length); + vallen); *offset = i + 1; } @@ -2449,7 +2449,7 @@ int altera_init(struct altera_config *config, const struct firmware *fw) __func__, (format_version == 2) ? "Jam STAPL" : "pre-standardized Jam 1.1"); while (altera_get_note((u8 *)fw->data, fw->size, - &offset, key, value, 256) == 0) + &offset, key, value, 32, 256) == 0) printk(KERN_INFO "%s: NOTE \"%s\" = \"%s\"\n", __func__, key, value); } |