| Message ID | 20200920170158.1217068-1-bryan.odonoghue@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | USB: gadget: f_ncm: Fix NDP16 datagram validation | expand |
On 9/20/20 1:01 PM, Bryan O'Donoghue wrote: > commit 2b74b0a04d3e ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") > adds important bounds checking however it unfortunately also introduces a > bug with respect to section 3.3.1 of the NCM specification. > > wDatagramIndex[1] : "Byte index, in little endian, of the second datagram > described by this NDP16. If zero, then this marks the end of the sequence > of datagrams in this NDP16." > > wDatagramLength[1]: "Byte length, in little endian, of the second datagram > described by this NDP16. If zero, then this marks the end of the sequence > of datagrams in this NDP16." > > wDatagramIndex[1] and wDatagramLength[1] respectively then may be zero but > that does not mean we should throw away the data referenced by > wDatagramIndex[0] and wDatagramLength[0] as is currently the case. > > Breaking the loop on (index2 == 0 || dg_len2 == 0) should come at the end > as was previously the case and checks for index2 and dg_len2 should be > removed since zero is valid. > > I'm not sure how much testing the above patch received but for me right now > after enumeration ping doesn't work. Reverting the commit restores ping, > scp, etc. > > The extra validation associated with wDatagramIndex[0] and > wDatagramLength[0] appears to be valid so, this change removes the incorrect > restriction on wDatagramIndex[1] and wDatagramLength[1] restoring data > processing between host and device. > > Fixes: 2b74b0a04d3e ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") > Cc: Ilja Van Sprundel <ivansprundel@ioactive.com> > Cc: Brooke Basile <brookebasile@gmail.com> > Cc: stable <stable@kernel.org> > Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> > --- > drivers/usb/gadget/function/f_ncm.c | 30 ++--------------------------- > 1 file changed, 2 insertions(+), 28 deletions(-) > > diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c > index b4206b0dede5..1f638759a953 100644 > --- a/drivers/usb/gadget/function/f_ncm.c > +++ b/drivers/usb/gadget/function/f_ncm.c > @@ -1189,7 +1189,6 @@ static int ncm_unwrap_ntb(struct gether *port, > const struct ndp_parser_opts *opts = ncm->parser_opts; > unsigned crc_len = ncm->is_crc ? sizeof(uint32_t) : 0; > int dgram_counter; > - bool ndp_after_header; > > /* dwSignature */ > if (get_unaligned_le32(tmp) != opts->nth_sign) { > @@ -1216,7 +1215,6 @@ static int ncm_unwrap_ntb(struct gether *port, > } > > ndp_index = get_ncm(&tmp, opts->ndp_index); > - ndp_after_header = false; > > /* Run through all the NDP's in the NTB */ > do { > @@ -1232,8 +1230,6 @@ static int ncm_unwrap_ntb(struct gether *port, > ndp_index); > goto err; > } > - if (ndp_index == opts->nth_size) > - ndp_after_header = true; > > /* > * walk through NDP > @@ -1312,37 +1308,13 @@ static int ncm_unwrap_ntb(struct gether *port, > index2 = get_ncm(&tmp, opts->dgram_item_len); > dg_len2 = get_ncm(&tmp, opts->dgram_item_len); > > - if (index2 == 0 || dg_len2 == 0) > - break; > - > /* wDatagramIndex[1] */ > - if (ndp_after_header) { > - if (index2 < opts->nth_size + opts->ndp_size) { > - INFO(port->func.config->cdev, > - "Bad index: %#X\n", index2); > - goto err; > - } > - } else { > - if (index2 < opts->nth_size + opts->dpe_size) { > - INFO(port->func.config->cdev, > - "Bad index: %#X\n", index2); > - goto err; > - } > - } > if (index2 > block_len - opts->dpe_size) { > INFO(port->func.config->cdev, > "Bad index: %#X\n", index2); > goto err; > } > > - /* wDatagramLength[1] */ > - if ((dg_len2 < 14 + crc_len) || > - (dg_len2 > frame_max)) { > - INFO(port->func.config->cdev, > - "Bad dgram length: %#X\n", dg_len); > - goto err; > - } > - > /* > * Copy the data into a new skb. > * This ensures the truesize is correct > @@ -1359,6 +1331,8 @@ static int ncm_unwrap_ntb(struct gether *port, > ndp_len -= 2 * (opts->dgram_item_len * 2); > > dgram_counter++; > + if (index2 == 0 || dg_len2 == 0) > + break; > } while (ndp_len > 2 * (opts->dgram_item_len * 2)); > } while (ndp_index); > > Bryan, Ah, I see my mistake. I did test this, but I must have missed some test cases as I didn't encounter this error. Thanks a lot for testing and fixing the issue, and for the thorough explanation. Best, Brooke Basile
On Sun, 2020-09-20 at 18:01 +0100, Bryan O'Donoghue wrote: > commit 2b74b0a04d3e ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") > adds important bounds checking however it unfortunately also introduces a > bug with respect to section 3.3.1 of the NCM specification. > > wDatagramIndex[1] : "Byte index, in little endian, of the second datagram > described by this NDP16. If zero, then this marks the end of the sequence > of datagrams in this NDP16." > > wDatagramLength[1]: "Byte length, in little endian, of the second datagram > described by this NDP16. If zero, then this marks the end of the sequence > of datagrams in this NDP16." > > wDatagramIndex[1] and wDatagramLength[1] respectively then may be zero but > that does not mean we should throw away the data referenced by > wDatagramIndex[0] and wDatagramLength[0] as is currently the case. > > Breaking the loop on (index2 == 0 || dg_len2 == 0) should come at the end > as was previously the case and checks for index2 and dg_len2 should be > removed since zero is valid. > > I'm not sure how much testing the above patch received but for me right now > after enumeration ping doesn't work. Reverting the commit restores ping, > scp, etc. Same regression for me. The last datagram of any NTB from the host is ignored so most networking is broken. With this patch, I'm able to communicate from host to device again. > The extra validation associated with wDatagramIndex[0] and > wDatagramLength[0] appears to be valid so, this change removes the incorrect > restriction on wDatagramIndex[1] and wDatagramLength[1] restoring data > processing between host and device. > > Fixes: 2b74b0a04d3e ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") > Cc: Ilja Van Sprundel <ivansprundel@ioactive.com> > Cc: Brooke Basile <brookebasile@gmail.com> > Cc: stable <stable@kernel.org> Tested-by: Harald Seiler <hws@denx.de> Reviewed-by: Harald Seiler <hws@denx.de> > Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> > --- > drivers/usb/gadget/function/f_ncm.c | 30 ++--------------------------- > 1 file changed, 2 insertions(+), 28 deletions(-) > > diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c > index b4206b0dede5..1f638759a953 100644 > --- a/drivers/usb/gadget/function/f_ncm.c > +++ b/drivers/usb/gadget/function/f_ncm.c > @@ -1189,7 +1189,6 @@ static int ncm_unwrap_ntb(struct gether *port, > const struct ndp_parser_opts *opts = ncm->parser_opts; > unsigned crc_len = ncm->is_crc ? sizeof(uint32_t) : 0; > int dgram_counter; > - bool ndp_after_header; > > /* dwSignature */ > if (get_unaligned_le32(tmp) != opts->nth_sign) { > @@ -1216,7 +1215,6 @@ static int ncm_unwrap_ntb(struct gether *port, > } > > ndp_index = get_ncm(&tmp, opts->ndp_index); > - ndp_after_header = false; > > /* Run through all the NDP's in the NTB */ > do { > @@ -1232,8 +1230,6 @@ static int ncm_unwrap_ntb(struct gether *port, > ndp_index); > goto err; > } > - if (ndp_index == opts->nth_size) > - ndp_after_header = true; > > /* > * walk through NDP > @@ -1312,37 +1308,13 @@ static int ncm_unwrap_ntb(struct gether *port, > index2 = get_ncm(&tmp, opts->dgram_item_len); > dg_len2 = get_ncm(&tmp, opts->dgram_item_len); > > - if (index2 == 0 || dg_len2 == 0) > - break; > - > /* wDatagramIndex[1] */ > - if (ndp_after_header) { > - if (index2 < opts->nth_size + opts->ndp_size) { > - INFO(port->func.config->cdev, > - "Bad index: %#X\n", index2); > - goto err; > - } > - } else { > - if (index2 < opts->nth_size + opts->dpe_size) { > - INFO(port->func.config->cdev, > - "Bad index: %#X\n", index2); > - goto err; > - } > - } > if (index2 > block_len - opts->dpe_size) { > INFO(port->func.config->cdev, > "Bad index: %#X\n", index2); > goto err; > } > > - /* wDatagramLength[1] */ > - if ((dg_len2 < 14 + crc_len) || > - (dg_len2 > frame_max)) { > - INFO(port->func.config->cdev, > - "Bad dgram length: %#X\n", dg_len); > - goto err; > - } > - > /* > * Copy the data into a new skb. > * This ensures the truesize is correct > @@ -1359,6 +1331,8 @@ static int ncm_unwrap_ntb(struct gether *port, > ndp_len -= 2 * (opts->dgram_item_len * 2); > > dgram_counter++; > + if (index2 == 0 || dg_len2 == 0) > + break; > } while (ndp_len > 2 * (opts->dgram_item_len * 2)); > } while (ndp_index); > > -- > 2.27.0 > -- Harald
Hello Greg, Hello stable maintainers, On Sun, Sep 20, 2020 at 06:01:58PM +0100, Bryan O'Donoghue wrote: > commit 2b74b0a04d3e ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") > adds important bounds checking however it unfortunately also introduces a > bug with respect to section 3.3.1 of the NCM specification. > > wDatagramIndex[1] : "Byte index, in little endian, of the second datagram > described by this NDP16. If zero, then this marks the end of the sequence > of datagrams in this NDP16." > > wDatagramLength[1]: "Byte length, in little endian, of the second datagram > described by this NDP16. If zero, then this marks the end of the sequence > of datagrams in this NDP16." > > wDatagramIndex[1] and wDatagramLength[1] respectively then may be zero but > that does not mean we should throw away the data referenced by > wDatagramIndex[0] and wDatagramLength[0] as is currently the case. > > Breaking the loop on (index2 == 0 || dg_len2 == 0) should come at the end > as was previously the case and checks for index2 and dg_len2 should be > removed since zero is valid. > > I'm not sure how much testing the above patch received but for me right now > after enumeration ping doesn't work. Reverting the commit restores ping, > scp, etc. > > The extra validation associated with wDatagramIndex[0] and > wDatagramLength[0] appears to be valid so, this change removes the incorrect > restriction on wDatagramIndex[1] and wDatagramLength[1] restoring data > processing between host and device. > > Fixes: 2b74b0a04d3e ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") > Cc: Ilja Van Sprundel <ivansprundel@ioactive.com> > Cc: Brooke Basile <brookebasile@gmail.com> > Cc: stable <stable@kernel.org> > Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> > --- > drivers/usb/gadget/function/f_ncm.c | 30 ++--------------------------- > 1 file changed, 2 insertions(+), 28 deletions(-) This patch appears to be pushed to 4.19, 5.4 and 5.8 stable trees via: https://lore.kernel.org/lkml/20201005142108.771915994@linuxfoundation.org/ https://lore.kernel.org/lkml/20201005142109.966570222@linuxfoundation.org/ https://lore.kernel.org/lkml/20201005142114.960807335@linuxfoundation.org/ Will you push this patch to v4.14.y, in order to fix v4.14.196 commit https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b88ad6e714284b ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") ? -- Best regards, Eugeniu Rosca
On Tue, Oct 06, 2020 at 08:29:43PM +0200, Eugeniu Rosca wrote: > Hello Greg, > Hello stable maintainers, > > On Sun, Sep 20, 2020 at 06:01:58PM +0100, Bryan O'Donoghue wrote: > > commit 2b74b0a04d3e ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") > > adds important bounds checking however it unfortunately also introduces a > > bug with respect to section 3.3.1 of the NCM specification. > > > > wDatagramIndex[1] : "Byte index, in little endian, of the second datagram > > described by this NDP16. If zero, then this marks the end of the sequence > > of datagrams in this NDP16." > > > > wDatagramLength[1]: "Byte length, in little endian, of the second datagram > > described by this NDP16. If zero, then this marks the end of the sequence > > of datagrams in this NDP16." > > > > wDatagramIndex[1] and wDatagramLength[1] respectively then may be zero but > > that does not mean we should throw away the data referenced by > > wDatagramIndex[0] and wDatagramLength[0] as is currently the case. > > > > Breaking the loop on (index2 == 0 || dg_len2 == 0) should come at the end > > as was previously the case and checks for index2 and dg_len2 should be > > removed since zero is valid. > > > > I'm not sure how much testing the above patch received but for me right now > > after enumeration ping doesn't work. Reverting the commit restores ping, > > scp, etc. > > > > The extra validation associated with wDatagramIndex[0] and > > wDatagramLength[0] appears to be valid so, this change removes the incorrect > > restriction on wDatagramIndex[1] and wDatagramLength[1] restoring data > > processing between host and device. > > > > Fixes: 2b74b0a04d3e ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") > > Cc: Ilja Van Sprundel <ivansprundel@ioactive.com> > > Cc: Brooke Basile <brookebasile@gmail.com> > > Cc: stable <stable@kernel.org> > > Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> > > --- > > drivers/usb/gadget/function/f_ncm.c | 30 ++--------------------------- > > 1 file changed, 2 insertions(+), 28 deletions(-) > > This patch appears to be pushed to 4.19, 5.4 and 5.8 stable trees via: > > https://lore.kernel.org/lkml/20201005142108.771915994@linuxfoundation.org/ > https://lore.kernel.org/lkml/20201005142109.966570222@linuxfoundation.org/ > https://lore.kernel.org/lkml/20201005142114.960807335@linuxfoundation.org/ > > Will you push this patch to v4.14.y, in order to fix v4.14.196 commit > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b88ad6e714284b > ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") ? It also need to go to 4.9.y, and is already queued up in the stable queues for those trees for the next round of kernels that are released for them. thanks, greg k-h
Hello again, On Tue, Oct 06, 2020 at 10:18:25PM +0200, Greg KH wrote: > On Tue, Oct 06, 2020 at 08:29:43PM +0200, Eugeniu Rosca wrote: > > On Sun, Sep 20, 2020 at 06:01:58PM +0100, Bryan O'Donoghue wrote: > > > commit 2b74b0a04d3e ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") [..] > > This patch appears to be pushed to 4.19, 5.4 and 5.8 stable trees via: > > > > https://lore.kernel.org/lkml/20201005142108.771915994@linuxfoundation.org/ > > https://lore.kernel.org/lkml/20201005142109.966570222@linuxfoundation.org/ > > https://lore.kernel.org/lkml/20201005142114.960807335@linuxfoundation.org/ > > > > Will you push this patch to v4.14.y, in order to fix v4.14.196 commit > > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b88ad6e714284b > > ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") ? > > It also need to go to 4.9.y, and is already queued up in the stable > queues for those trees for the next round of kernels that are released > for them. Thank you! -- Best regards, Eugeniu Rosca
diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c index b4206b0dede5..1f638759a953 100644 --- a/drivers/usb/gadget/function/f_ncm.c +++ b/drivers/usb/gadget/function/f_ncm.c @@ -1189,7 +1189,6 @@ static int ncm_unwrap_ntb(struct gether *port, const struct ndp_parser_opts *opts = ncm->parser_opts; unsigned crc_len = ncm->is_crc ? sizeof(uint32_t) : 0; int dgram_counter; - bool ndp_after_header; /* dwSignature */ if (get_unaligned_le32(tmp) != opts->nth_sign) { @@ -1216,7 +1215,6 @@ static int ncm_unwrap_ntb(struct gether *port, } ndp_index = get_ncm(&tmp, opts->ndp_index); - ndp_after_header = false; /* Run through all the NDP's in the NTB */ do { @@ -1232,8 +1230,6 @@ static int ncm_unwrap_ntb(struct gether *port, ndp_index); goto err; } - if (ndp_index == opts->nth_size) - ndp_after_header = true; /* * walk through NDP @@ -1312,37 +1308,13 @@ static int ncm_unwrap_ntb(struct gether *port, index2 = get_ncm(&tmp, opts->dgram_item_len); dg_len2 = get_ncm(&tmp, opts->dgram_item_len); - if (index2 == 0 || dg_len2 == 0) - break; - /* wDatagramIndex[1] */ - if (ndp_after_header) { - if (index2 < opts->nth_size + opts->ndp_size) { - INFO(port->func.config->cdev, - "Bad index: %#X\n", index2); - goto err; - } - } else { - if (index2 < opts->nth_size + opts->dpe_size) { - INFO(port->func.config->cdev, - "Bad index: %#X\n", index2); - goto err; - } - } if (index2 > block_len - opts->dpe_size) { INFO(port->func.config->cdev, "Bad index: %#X\n", index2); goto err; } - /* wDatagramLength[1] */ - if ((dg_len2 < 14 + crc_len) || - (dg_len2 > frame_max)) { - INFO(port->func.config->cdev, - "Bad dgram length: %#X\n", dg_len); - goto err; - } - /* * Copy the data into a new skb. * This ensures the truesize is correct @@ -1359,6 +1331,8 @@ static int ncm_unwrap_ntb(struct gether *port, ndp_len -= 2 * (opts->dgram_item_len * 2); dgram_counter++; + if (index2 == 0 || dg_len2 == 0) + break; } while (ndp_len > 2 * (opts->dgram_item_len * 2)); } while (ndp_index);
commit 2b74b0a04d3e ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") adds important bounds checking however it unfortunately also introduces a bug with respect to section 3.3.1 of the NCM specification. wDatagramIndex[1] : "Byte index, in little endian, of the second datagram described by this NDP16. If zero, then this marks the end of the sequence of datagrams in this NDP16." wDatagramLength[1]: "Byte length, in little endian, of the second datagram described by this NDP16. If zero, then this marks the end of the sequence of datagrams in this NDP16." wDatagramIndex[1] and wDatagramLength[1] respectively then may be zero but that does not mean we should throw away the data referenced by wDatagramIndex[0] and wDatagramLength[0] as is currently the case. Breaking the loop on (index2 == 0 || dg_len2 == 0) should come at the end as was previously the case and checks for index2 and dg_len2 should be removed since zero is valid. I'm not sure how much testing the above patch received but for me right now after enumeration ping doesn't work. Reverting the commit restores ping, scp, etc. The extra validation associated with wDatagramIndex[0] and wDatagramLength[0] appears to be valid so, this change removes the incorrect restriction on wDatagramIndex[1] and wDatagramLength[1] restoring data processing between host and device. Fixes: 2b74b0a04d3e ("USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb()") Cc: Ilja Van Sprundel <ivansprundel@ioactive.com> Cc: Brooke Basile <brookebasile@gmail.com> Cc: stable <stable@kernel.org> Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> --- drivers/usb/gadget/function/f_ncm.c | 30 ++--------------------------- 1 file changed, 2 insertions(+), 28 deletions(-)