From: Daniel Axtens dja@axtens.net
[ Upstream commit 3745488e9d599916a0b40d45d3f30e3d4720288e ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/misc/altera-stapl/altera.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/misc/altera-stapl/altera.c b/drivers/misc/altera-stapl/altera.c index d2ed3b9728b7c..94bde09d9323d 100644 --- a/drivers/misc/altera-stapl/altera.c +++ b/drivers/misc/altera-stapl/altera.c @@ -2126,8 +2126,8 @@ static int altera_execute(struct altera_state *astate, 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, @@ -2184,7 +2184,7 @@ 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);
} } @@ -2203,13 +2203,13 @@ 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; } @@ -2463,7 +2463,7 @@ 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); }