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CVE-2017-1000410 CrOS: Vulnerability reported in Linux kernel |
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Issue descriptionVOMIT (go/vomit) has received an external vulnerability report for the Linux kernel. Advisory: CVE-2017-1000410 Details: http://vomit.googleplex.com/advisory?id=CVE/CVE-2017-1000410 CVSS severity score: 5/10.0 Description: The Linux kernel version 3.3-rc1 and later is affected by a vulnerability lies in the processing of incoming L2CAP commands - ConfigRequest, and ConfigResponse messages. This info leak is a result of uninitialized stack variables that may be returned to an attacker in their uninitialized state. By manipulating the code flows that precede the handling of these configuration messages, an attacker can also gain some control over which data will be held in the uninitialized stack variables. This can allow him to bypass KASLR, and stack canaries protection - as both pointers and stack canaries may be leaked in this manner. Combining this vulnerability (for example) with the previously disclosed RCE vulnerability in L2CAP configuration parsing (CVE-2017-1000251) may allow an attacker to exploit the RCE against kernels which were built with the above mitigations. These are the specifics of this vulnerability: In the function l2cap_parse_conf_rsp and in the function l2cap_parse_conf_req the following variable is declared without initialization: struct l2cap_conf_efs efs; In addition, when parsing input configuration parameters in both of these functions, the switch case for handling EFS elements may skip the memcpy call that will write to the efs variable: ... case L2CAP_CONF_EFS: if (olen == sizeof(efs)) memcpy(&efs, (void *)val, olen); ... The olen in the above if is attacker controlled, and regardless of that if, in both of these functions the efs variable would eventually be added to the outgoing configuration request that is being built: l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs), (unsigned long) &efs); So by sending a configuration request, or response, that contains an L2CAP_CONF_EFS element, but with an element length that is not sizeof(efs) - the memcpy to the uninitialized efs variable can be avoided, and the uninitialized variable would be returned to the attacker (16 bytes). This bug was filed by http://go/vomit Please contact us at vomit-team@google.com if you need any assistance.
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Dec 22 2017
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Jan 2 2018
No progress upstream. Will go ahead and apply directly. No plan to apply to stable releases.
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Jan 2 2018
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Jan 2 2018
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Jan 2 2018
Bug in bluetooth. No impact on lakitu.
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Jan 3 2018
The following revision refers to this bug: https://chromium.googlesource.com/chromiumos/third_party/kernel/+/0e09b163c371dafcedbdad49dde6963b746e5fed commit 0e09b163c371dafcedbdad49dde6963b746e5fed Author: Ben Seri <ben@armis.com> Date: Wed Jan 03 22:23:30 2018 FROMLIST: Bluetooth: Prevent stack info leak from the EFS element. In the function l2cap_parse_conf_rsp and in the function l2cap_parse_conf_req the following variable is declared without initialization: struct l2cap_conf_efs efs; In addition, when parsing input configuration parameters in both of these functions, the switch case for handling EFS elements may skip the memcpy call that will write to the efs variable: ... case L2CAP_CONF_EFS: if (olen == sizeof(efs)) memcpy(&efs, (void *)val, olen); ... The olen in the above if is attacker controlled, and regardless of that if, in both of these functions the efs variable would eventually be added to the outgoing configuration request that is being built: l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs), (unsigned long) &efs); So by sending a configuration request, or response, that contains an L2CAP_CONF_EFS element, but with an element length that is not sizeof(efs) - the memcpy to the uninitialized efs variable can be avoided, and the uninitialized variable would be returned to the attacker (16 bytes). This issue has been assigned CVE-2017-1000410 BUG= chromium:797254 TEST=Build and run Change-Id: Ibf1dbfd30959d6ffe51d8b95e82185e57c75b1ce Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Gustavo Padovan <gustavo@padovan.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Ben Seri <ben@armis.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Guenter Roeck <groeck@chromium.org> (am from https://patchwork.kernel.org/patch/10102605/) Reviewed-on: https://chromium-review.googlesource.com/847703 Reviewed-by: Ben Chan <benchan@chromium.org> Reviewed-by: Miao-chen Chou <mcchou@chromium.org> [modify] https://crrev.com/0e09b163c371dafcedbdad49dde6963b746e5fed/net/bluetooth/l2cap_core.c
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Jan 4 2018
The following revision refers to this bug: https://chromium.googlesource.com/chromiumos/third_party/kernel/+/f6180a1523f396a1570b3fefd04f876c595af5af commit f6180a1523f396a1570b3fefd04f876c595af5af Author: Ben Seri <ben@armis.com> Date: Thu Jan 04 06:43:02 2018 FROMLIST: Bluetooth: Prevent stack info leak from the EFS element. In the function l2cap_parse_conf_rsp and in the function l2cap_parse_conf_req the following variable is declared without initialization: struct l2cap_conf_efs efs; In addition, when parsing input configuration parameters in both of these functions, the switch case for handling EFS elements may skip the memcpy call that will write to the efs variable: ... case L2CAP_CONF_EFS: if (olen == sizeof(efs)) memcpy(&efs, (void *)val, olen); ... The olen in the above if is attacker controlled, and regardless of that if, in both of these functions the efs variable would eventually be added to the outgoing configuration request that is being built: l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs), (unsigned long) &efs); So by sending a configuration request, or response, that contains an L2CAP_CONF_EFS element, but with an element length that is not sizeof(efs) - the memcpy to the uninitialized efs variable can be avoided, and the uninitialized variable would be returned to the attacker (16 bytes). This issue has been assigned CVE-2017-1000410 BUG= chromium:797254 TEST=Build and run Change-Id: Ibf1dbfd30959d6ffe51d8b95e82185e57c75b1ce Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Gustavo Padovan <gustavo@padovan.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Ben Seri <ben@armis.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Guenter Roeck <groeck@chromium.org> (am from https://patchwork.kernel.org/patch/10102605/) Reviewed-on: https://chromium-review.googlesource.com/847703 Reviewed-by: Ben Chan <benchan@chromium.org> Reviewed-by: Miao-chen Chou <mcchou@chromium.org> (cherry picked from commit 0e09b163c371dafcedbdad49dde6963b746e5fed) Reviewed-on: https://chromium-review.googlesource.com/849435 [modify] https://crrev.com/f6180a1523f396a1570b3fefd04f876c595af5af/net/bluetooth/l2cap_core.c
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Jan 4 2018
The following revision refers to this bug: https://chromium.googlesource.com/chromiumos/third_party/kernel/+/a6c1ef4067c9b53a111d077df2a36054a73cdd0f commit a6c1ef4067c9b53a111d077df2a36054a73cdd0f Author: Ben Seri <ben@armis.com> Date: Thu Jan 04 06:43:00 2018 FROMLIST: Bluetooth: Prevent stack info leak from the EFS element. In the function l2cap_parse_conf_rsp and in the function l2cap_parse_conf_req the following variable is declared without initialization: struct l2cap_conf_efs efs; In addition, when parsing input configuration parameters in both of these functions, the switch case for handling EFS elements may skip the memcpy call that will write to the efs variable: ... case L2CAP_CONF_EFS: if (olen == sizeof(efs)) memcpy(&efs, (void *)val, olen); ... The olen in the above if is attacker controlled, and regardless of that if, in both of these functions the efs variable would eventually be added to the outgoing configuration request that is being built: l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs), (unsigned long) &efs); So by sending a configuration request, or response, that contains an L2CAP_CONF_EFS element, but with an element length that is not sizeof(efs) - the memcpy to the uninitialized efs variable can be avoided, and the uninitialized variable would be returned to the attacker (16 bytes). This issue has been assigned CVE-2017-1000410 BUG= chromium:797254 TEST=Build and run Change-Id: Ibf1dbfd30959d6ffe51d8b95e82185e57c75b1ce Cc: Marcel Holtmann <marcel@holtmann.org> Cc: Gustavo Padovan <gustavo@padovan.org> Cc: Johan Hedberg <johan.hedberg@gmail.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Ben Seri <ben@armis.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Guenter Roeck <groeck@chromium.org> (am from https://patchwork.kernel.org/patch/10102605/) Reviewed-on: https://chromium-review.googlesource.com/847703 Reviewed-by: Ben Chan <benchan@chromium.org> Reviewed-by: Miao-chen Chou <mcchou@chromium.org> (cherry picked from commit 0e09b163c371dafcedbdad49dde6963b746e5fed) Reviewed-on: https://chromium-review.googlesource.com/849436 [modify] https://crrev.com/a6c1ef4067c9b53a111d077df2a36054a73cdd0f/net/bluetooth/l2cap_core.c
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Jan 4 2018
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Jan 5 2018
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Apr 13 2018
This bug has been closed for more than 14 weeks. Removing security view restrictions. For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot |
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Comment 1 by groeck@chromium.org
, Dec 22 2017Labels: Security_Severity-Medium Security_Impact-Stable M-65 Pri-1
Status: ExternalDependency (was: Untriaged)