From: Yalagada Pavan Kumar <[email protected]> When reading the EEPROM address length, e100_eeprom_read() can return an invalid length. This value is then used as a shift count when calculating eeprom_wc, resulting in a shift-out-of-bounds UBSAN warning.
Stop EEPROM address probing if the detected address length exceeds the initial address length to prevent addr_len from underflowing. Validate addr_len after reading it from the EEPROM in both e100_eeprom_load() and e100_eeprom_save(), and return -EIO if the value is zero or greater than 8. Reported-by: [email protected] Closes: https://syzkaller.appspot.com/bug?extid=e0abb1d45ac291ebebeb Signed-off-by: Yalagada Pavan Kumar <[email protected]> --- v4: - Squash the v1-v3 changes into a single standalone patch. - Prevent addr_len underflow during EEPROM probing. - Validate addr_len in e100_eeprom_load() and e100_eeprom_save(). - Use BIT() and cast the result to u16 for eeprom_wc. - Target iwl-next as requested by Tony Nguyen. v3: https://lore.kernel.org/all/[email protected]/T/ v2: https://lore.kernel.org/all/[email protected]/T/ v1: https://lore.kernel.org/all/[email protected]/T/ --- drivers/net/ethernet/intel/e100.c | 29 ++++++++++++++++++++++++++--- 1 file changed, 26 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/intel/e100.c b/drivers/net/ethernet/intel/e100.c index 29960762e64a..cd8190386652 100644 --- a/drivers/net/ethernet/intel/e100.c +++ b/drivers/net/ethernet/intel/e100.c @@ -744,7 +744,14 @@ static __le16 e100_eeprom_read(struct nic *nic, u16 *addr_len, u16 addr) * complete address. Use this to adjust addr_len. */ ctrl = ioread8(&nic->csr->eeprom_ctrl_lo); if (!(ctrl & eedo) && i > 16) { - *addr_len -= (i - 16); + u16 len = i - 16; + + if (len > *addr_len) { + *addr_len = 0; + break; + } + + *addr_len -= len; i = 17; } @@ -765,7 +772,15 @@ static int e100_eeprom_load(struct nic *nic) /* Try reading with an 8-bit addr len to discover actual addr len */ e100_eeprom_read(nic, &addr_len, 0); - nic->eeprom_wc = 1 << addr_len; + + if (!addr_len || addr_len > 8) { + netif_err(nic, probe, nic->netdev, + "Invalid EEPROM address length %u\n", + addr_len); + return -EIO; + } + + nic->eeprom_wc = (u16)BIT(addr_len); for (addr = 0; addr < nic->eeprom_wc; addr++) { nic->eeprom[addr] = e100_eeprom_read(nic, &addr_len, addr); @@ -791,7 +806,15 @@ static int e100_eeprom_save(struct nic *nic, u16 start, u16 count) /* Try reading with an 8-bit addr len to discover actual addr len */ e100_eeprom_read(nic, &addr_len, 0); - nic->eeprom_wc = 1 << addr_len; + + if (!addr_len || addr_len > 8) { + netif_err(nic, probe, nic->netdev, + "Invalid EEPROM address length %u\n", + addr_len); + return -EIO; + } + + nic->eeprom_wc = (u16)BIT(addr_len); if (start + count >= nic->eeprom_wc) return -EINVAL; -- 2.43.0
