diff options
| author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2021-04-21 21:46:36 +0200 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2021-05-22 14:05:37 +0200 |
| commit | 942859d969de7f6f7f2659a79237a758b42782da (patch) | |
| tree | a49a607f9725836b719f1054870d4503b2380a65 | |
| parent | c4039b29fe9637e1135912813f830994af4c867f (diff) | |
| download | linux-next-942859d969de7f6f7f2659a79237a758b42782da.tar.gz | |
efi: cper: fix snprintf() use in cper_dimm_err_location()
snprintf() should be given the full buffer size, not one less. And it
guarantees nul-termination, so doing it manually afterwards is
pointless.
It's even potentially harmful (though probably not in practice because
CPER_REC_LEN is 256), due to the "return how much would have been
written had the buffer been big enough" semantics. I.e., if the bank
and/or device strings are long enough that the "DIMM location ..."
output gets truncated, writing to msg[n] is a buffer overflow.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Fixes: 3760cd20402d4 ("CPER: Adjust code flow of some functions")
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
| -rw-r--r-- | drivers/firmware/efi/cper.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c index e15d484b6a5a..ea7ca74fc173 100644 --- a/drivers/firmware/efi/cper.c +++ b/drivers/firmware/efi/cper.c @@ -276,8 +276,7 @@ static int cper_dimm_err_location(struct cper_mem_err_compact *mem, char *msg) if (!msg || !(mem->validation_bits & CPER_MEM_VALID_MODULE_HANDLE)) return 0; - n = 0; - len = CPER_REC_LEN - 1; + len = CPER_REC_LEN; dmi_memdev_name(mem->mem_dev_handle, &bank, &device); if (bank && device) n = snprintf(msg, len, "DIMM location: %s %s ", bank, device); @@ -286,7 +285,6 @@ static int cper_dimm_err_location(struct cper_mem_err_compact *mem, char *msg) "DIMM location: not present. DMI handle: 0x%.4x ", mem->mem_dev_handle); - msg[n] = '\0'; return n; } |