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| author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2021-04-21 22:46:36 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-06-10 14:24:04 +0300 |
| commit | dd47a33e11fdd6c9d31570500e6ecc369ba1f08e (patch) | |
| tree | 0229dc328201a0454c5ba8163e919e1c4480a384 /drivers/firmware/efi/cper.c | |
| parent | 5fdb418b14e41b33880b949db64b18f1f448916b (diff) | |
| download | linux-dd47a33e11fdd6c9d31570500e6ecc369ba1f08e.tar.xz | |
efi: cper: fix snprintf() use in cper_dimm_err_location()
[ Upstream commit 942859d969de7f6f7f2659a79237a758b42782da ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/firmware/efi/cper.c')
| -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 116989cf3d45..97da083afd32 100644 --- a/drivers/firmware/efi/cper.c +++ b/drivers/firmware/efi/cper.c @@ -275,8 +275,7 @@ 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); @@ -285,7 +284,6 @@ 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; } |