diff options
| author | Heinrich Schuchardt <heinrich.schuchardt@canonical.com> | 2024-01-04 04:49:42 +0100 |
|---|---|---|
| committer | Jaehoon Chung <jh80.chung@samsung.com> | 2024-04-15 15:19:11 +0900 |
| commit | f9a86fb118530fea5a87dd7f88e90c31c989043f (patch) | |
| tree | 8568b92d2b805c9b3805dc6905510deaa1f57bcd | |
| parent | b03b49046af5dfca599d2ce8f0aafed89b97aa91 (diff) | |
| download | u-boot-f9a86fb118530fea5a87dd7f88e90c31c989043f.zip u-boot-f9a86fb118530fea5a87dd7f88e90c31c989043f.tar.gz u-boot-f9a86fb118530fea5a87dd7f88e90c31c989043f.tar.bz2 | |
mmc: Avoid buffer overrun in mmc_startup()
If the CSD register contains a reserved value (4 - 7) in bits 0:2 of the
TRAN_SPEED field, a buffer overrun occurs. Resize the mapping table.
According to the original report
https://lore.kernel.org/u-boot/20180826231332.2491-11-erosca@de.adit-jv.com/
reserved values have been observed resulting in a buffer overrun.
Reported-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Fixes: 272cc70b211e ("Add MMC Framework")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
| -rw-r--r-- | drivers/mmc/mmc.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index d96db7a..00f4964 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -1570,13 +1570,20 @@ static int sd_read_ssr(struct mmc *mmc) return 0; } #endif -/* frequency bases */ -/* divided by 10 to be nice to platforms without floating point */ +/* + * TRAN_SPEED bits 0:2 encode the frequency unit: + * 0 = 100KHz, 1 = 1MHz, 2 = 10MHz, 3 = 100MHz, values 4 - 7 are reserved. + * The values in fbase[] are divided by 10 to avoid floats in multiplier[]. + */ static const int fbase[] = { 10000, 100000, 1000000, 10000000, + 0, /* reserved */ + 0, /* reserved */ + 0, /* reserved */ + 0, /* reserved */ }; /* Multiplier values for TRAN_SPEED. Multiplied by 10 to be nice @@ -2560,6 +2567,8 @@ static int mmc_startup(struct mmc *mmc) mult = multipliers[((cmd.response[0] >> 3) & 0xf)]; mmc->legacy_speed = freq * mult; + if (!mmc->legacy_speed) + log_debug("TRAN_SPEED: reserved value"); mmc_select_mode(mmc, MMC_LEGACY); mmc->dsr_imp = ((cmd.response[1] >> 12) & 0x1); |