From: Yalagada Pavan Kumar <[email protected]> When reading the EEPROM address length, e100_eeprom_read() can return an invalid length (0 or >= 16). Passing an invalid addr_len to bit-shift operations causes a shift out-of-bounds, triggering a kernel panic or UBSAN warning.
Validate addr_len after reading it from EEPROM in both e100_eeprom_load() and e100_eeprom_save(), and return -EIO if the value is out of bounds. Reported-by: [email protected] Closes: https://syzkaller.appspot.com/bug?extid=e0abb1d45ac291ebebeb Signed-off-by: Yalagada Pavan Kumar <[email protected]> --- Tested in QEMU using syzbot c reproducer. v2: - Return -EIO instead of -EINVAL for an invalid EEPROM address length. - Validate addr_len in e100_eeprom_save() as well. - Drop the unnecessary 1U change in the shift. - Update the commit message. v1: https://lore.kernel.org/all/[email protected]/T/ --- drivers/net/ethernet/intel/e100.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/e100.c b/drivers/net/ethernet/intel/e100.c index 1de5cd41ea0c..464dc2d6cdb5 100644 --- a/drivers/net/ethernet/intel/e100.c +++ b/drivers/net/ethernet/intel/e100.c @@ -775,10 +775,10 @@ static int e100_eeprom_load(struct nic *nic) netif_err(nic, probe, nic->netdev, "Invalid EEPROM address length %u\n", addr_len); - return -EINVAL; + return -EIO; } - nic->eeprom_wc = 1U << addr_len; + nic->eeprom_wc = 1 << addr_len; for (addr = 0; addr < nic->eeprom_wc; addr++) { nic->eeprom[addr] = e100_eeprom_read(nic, &addr_len, addr); @@ -804,6 +804,14 @@ 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); + + if (!addr_len || addr_len >= 16) { + netif_err(nic, probe, nic->netdev, + "Invalid EEPROM address length %u\n", + addr_len); + return -EIO; + } + nic->eeprom_wc = 1 << addr_len; if (start + count >= nic->eeprom_wc) -- 2.43.0
