* [PATCH] e100: prevent shift out-of-bounds in e100_eeprom_load @ 2026-08-07 14:56 ` pavankumaryalagada 0 siblings, 0 replies; 4+ messages in thread From: pavankumaryalagada @ 2026-08-07 14:56 UTC (permalink / raw) To: intel-wired-lan, netdev Cc: anthony.l.nguyen, przemyslaw.kitszel, andrew+netdev, davem, edumazet, kuba, pabeni, linux-kernel, skhan, pavankumaryalagada, syzbot+e0abb1d45ac291ebebeb From: Yalagada Pavan Kumar <pavankumaryalagada@gmail.com> 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 and return -EINVAL if the value is out of bounds. Additionally, use 1U to prevent signed integer overflow when calculating eeprom_wc. Reported-by: syzbot+e0abb1d45ac291ebebeb@syzkaller.appspotmail.com Tested-by: syzbot+e0abb1d45ac291ebebeb@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=e0abb1d45ac291ebebeb Signed-off-by: Yalagada Pavan Kumar <pavankumaryalagada@gmail.com> --- Tested using syzbot c reproducer. --- drivers/net/ethernet/intel/e100.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/e100.c b/drivers/net/ethernet/intel/e100.c index 29960762e64a..1de5cd41ea0c 100644 --- a/drivers/net/ethernet/intel/e100.c +++ b/drivers/net/ethernet/intel/e100.c @@ -744,7 +744,12 @@ 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; + else + *addr_len -= len; i = 17; } @@ -765,7 +770,15 @@ 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 >= 16) { + netif_err(nic, probe, nic->netdev, + "Invalid EEPROM address length %u\n", + addr_len); + return -EINVAL; + } + + nic->eeprom_wc = 1U << addr_len; for (addr = 0; addr < nic->eeprom_wc; addr++) { nic->eeprom[addr] = e100_eeprom_read(nic, &addr_len, addr); -- 2.43.0 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* [Intel-wired-lan] [PATCH] e100: prevent shift out-of-bounds in e100_eeprom_load @ 2026-08-07 14:56 ` pavankumaryalagada 0 siblings, 0 replies; 4+ messages in thread From: pavankumaryalagada @ 2026-08-07 14:56 UTC (permalink / raw) To: intel-wired-lan, netdev Cc: anthony.l.nguyen, przemyslaw.kitszel, andrew+netdev, davem, edumazet, kuba, pabeni, linux-kernel, skhan, pavankumaryalagada, syzbot+e0abb1d45ac291ebebeb From: Yalagada Pavan Kumar <pavankumaryalagada@gmail.com> 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 and return -EINVAL if the value is out of bounds. Additionally, use 1U to prevent signed integer overflow when calculating eeprom_wc. Reported-by: syzbot+e0abb1d45ac291ebebeb@syzkaller.appspotmail.com Tested-by: syzbot+e0abb1d45ac291ebebeb@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=e0abb1d45ac291ebebeb Signed-off-by: Yalagada Pavan Kumar <pavankumaryalagada@gmail.com> --- Tested using syzbot c reproducer. --- drivers/net/ethernet/intel/e100.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/intel/e100.c b/drivers/net/ethernet/intel/e100.c index 29960762e64a..1de5cd41ea0c 100644 --- a/drivers/net/ethernet/intel/e100.c +++ b/drivers/net/ethernet/intel/e100.c @@ -744,7 +744,12 @@ 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; + else + *addr_len -= len; i = 17; } @@ -765,7 +770,15 @@ 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 >= 16) { + netif_err(nic, probe, nic->netdev, + "Invalid EEPROM address length %u\n", + addr_len); + return -EINVAL; + } + + nic->eeprom_wc = 1U << addr_len; for (addr = 0; addr < nic->eeprom_wc; addr++) { nic->eeprom[addr] = e100_eeprom_read(nic, &addr_len, addr); -- 2.43.0 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Intel-wired-lan] [PATCH] e100: prevent shift out-of-bounds in e100_eeprom_load 2026-08-07 14:56 ` [Intel-wired-lan] " pavankumaryalagada (?) @ 2026-08-08 15:12 ` Kohei Enju 2026-08-08 19:09 ` Yalagada Pavan Kumar -1 siblings, 1 reply; 4+ messages in thread From: Kohei Enju @ 2026-08-08 15:12 UTC (permalink / raw) To: pavankumaryalagada Cc: intel-wired-lan, netdev, anthony.l.nguyen, przemyslaw.kitszel, andrew+netdev, davem, edumazet, kuba, pabeni, linux-kernel, skhan, syzbot+e0abb1d45ac291ebebeb On 08/07 20:26, pavankumaryalagada@gmail.com wrote: > From: Yalagada Pavan Kumar <pavankumaryalagada@gmail.com> > > 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 and return -EINVAL if > the value is out of bounds. Additionally, use 1U to prevent > signed integer overflow when calculating eeprom_wc. > > Reported-by: syzbot+e0abb1d45ac291ebebeb@syzkaller.appspotmail.com > Tested-by: syzbot+e0abb1d45ac291ebebeb@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=e0abb1d45ac291ebebeb > Signed-off-by: Yalagada Pavan Kumar <pavankumaryalagada@gmail.com> > --- > Tested using syzbot c reproducer. > --- > drivers/net/ethernet/intel/e100.c | 17 +++++++++++++++-- > 1 file changed, 15 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/ethernet/intel/e100.c b/drivers/net/ethernet/intel/e100.c > index 29960762e64a..1de5cd41ea0c 100644 > --- a/drivers/net/ethernet/intel/e100.c > +++ b/drivers/net/ethernet/intel/e100.c > @@ -744,7 +744,12 @@ 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; > + else > + *addr_len -= len; > i = 17; > } > > @@ -765,7 +770,15 @@ 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 >= 16) { > + netif_err(nic, probe, nic->netdev, > + "Invalid EEPROM address length %u\n", > + addr_len); > + return -EINVAL; An invalid address length here appears to indicate an unexpected response from the EEPROM, rather than an invalid argument. Therefore, -EINVAL seems somewhat misleading. Would -EIO be more appropriate here? Also, e100_eeprom_save() seems to have the same pattern. Shouldn't we fix that as well? > + } > + > + nic->eeprom_wc = 1U << addr_len; The commit message says that the U suffix prevents signed integer overflow. However, after the validation addr_len is in [1, 15], so 1 << addr_len cannot overflow an int. I think what prevents the out-of-bounds shift is the validation, not the U. > > for (addr = 0; addr < nic->eeprom_wc; addr++) { > nic->eeprom[addr] = e100_eeprom_read(nic, &addr_len, addr); > -- > 2.43.0 > ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Intel-wired-lan] [PATCH] e100: prevent shift out-of-bounds in e100_eeprom_load 2026-08-08 15:12 ` Kohei Enju @ 2026-08-08 19:09 ` Yalagada Pavan Kumar 0 siblings, 0 replies; 4+ messages in thread From: Yalagada Pavan Kumar @ 2026-08-08 19:09 UTC (permalink / raw) To: Kohei Enju Cc: intel-wired-lan, netdev, anthony.l.nguyen, przemyslaw.kitszel, andrew+netdev, davem, edumazet, kuba, pabeni, linux-kernel, skhan, syzbot+e0abb1d45ac291ebebeb On Sun, Aug 09, 2026 at 12:12:31AM +0900, Kohei Enju wrote: > On 08/07 20:26, pavankumaryalagada@gmail.com wrote: > > From: Yalagada Pavan Kumar <pavankumaryalagada@gmail.com> > > > > 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 and return -EINVAL if > > the value is out of bounds. Additionally, use 1U to prevent > > signed integer overflow when calculating eeprom_wc. > > > > Reported-by: syzbot+e0abb1d45ac291ebebeb@syzkaller.appspotmail.com > > Tested-by: syzbot+e0abb1d45ac291ebebeb@syzkaller.appspotmail.com > > Closes: https://syzkaller.appspot.com/bug?extid=e0abb1d45ac291ebebeb > > Signed-off-by: Yalagada Pavan Kumar <pavankumaryalagada@gmail.com> > > --- > > Tested using syzbot c reproducer. > > --- > > drivers/net/ethernet/intel/e100.c | 17 +++++++++++++++-- > > 1 file changed, 15 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/net/ethernet/intel/e100.c b/drivers/net/ethernet/intel/e100.c > > index 29960762e64a..1de5cd41ea0c 100644 > > --- a/drivers/net/ethernet/intel/e100.c > > +++ b/drivers/net/ethernet/intel/e100.c > > @@ -744,7 +744,12 @@ 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; > > + else > > + *addr_len -= len; > > i = 17; > > } > > > > @@ -765,7 +770,15 @@ 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 >= 16) { > > + netif_err(nic, probe, nic->netdev, > > + "Invalid EEPROM address length %u\n", > > + addr_len); > > + return -EINVAL; > > An invalid address length here appears to indicate an unexpected > response from the EEPROM, rather than an invalid argument. Therefore, > -EINVAL seems somewhat misleading. Would -EIO be more appropriate here? Agreed, addr_len comes from an unexpected EEPROM response, so i will change -EINVAL to -EIO. > > Also, e100_eeprom_save() seems to have the same pattern. Shouldn't we > fix that as well? yes, i'll fix e100_eeprom_save() as well. > > > + } > > + > > + nic->eeprom_wc = 1U << addr_len; > > The commit message says that the U suffix prevents signed integer > overflow. However, after the validation addr_len is in [1, 15], so 1 << > addr_len cannot overflow an int. I think what prevents the out-of-bounds > shift is the validation, not the U. Agreed, I'll remove the unnecessary U suffix. I made these changes and will send v2. > > > > > for (addr = 0; addr < nic->eeprom_wc; addr++) { > > nic->eeprom[addr] = e100_eeprom_read(nic, &addr_len, addr); > > -- > > 2.43.0 > > ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-08-08 19:10 UTC | newest] Thread overview: 4+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2026-08-07 14:56 [PATCH] e100: prevent shift out-of-bounds in e100_eeprom_load pavankumaryalagada 2026-08-07 14:56 ` [Intel-wired-lan] " pavankumaryalagada 2026-08-08 15:12 ` Kohei Enju 2026-08-08 19:09 ` Yalagada Pavan Kumar
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