kernel/linux.git/drivers/usb/gadget/function/f_tcm.c, branch v6.6.150

usb: gadget: f_tcm: Fix NULL pointer dereferences in nexus handling

2026-03-25T10:05:57+00:00

[ Upstream commit b9fde507355342a2d64225d582dc8b98ff5ecb19 ] The `tpg->tpg_nexus` pointer in the USB Target driver is dynamically managed and tied to userspace configuration via ConfigFS. It can be NULL if the USB host sends requests before the nexus is fully established or immediately after it is dropped. Currently, functions like `bot_submit_command()` and the data transfer paths retrieve `tv_nexus = tpg->tpg_nexus` and immediately dereference `tv_nexus->tvn_se_sess` without any validation. If a malicious or misconfigured USB host sends a BOT (Bulk-Only Transport) command during this race window, it triggers a NULL pointer dereference, leading to a kernel panic (local DoS). This exposes an inconsistent API usage within the module, as peer functions like `usbg_submit_command()` and `bot_send_bad_response()` correctly implement a NULL check for `tv_nexus` before proceeding. Fix this by bringing consistency to the nexus handling. Add the missing `if (!tv_nexus)` checks to the vulnerable BOT command and request processing paths, aborting the command gracefully with an error instead of crashing the system. Fixes: c52661d60f63 ("usb-gadget: Initial merge of target module for UASP + BOT") Cc: stable Signed-off-by: Jiasheng Jiang Reviewed-by: Thinh Nguyen Link: https://patch.msgid.link/20260219023834.17976-1-jiashengjiangcool@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

usb: potential integer overflow in usbg_make_tpg()

2025-07-06T09:00:07+00:00

[ Upstream commit 153874010354d050f62f8ae25cbb960c17633dc5 ] The variable tpgt in usbg_make_tpg() is defined as unsigned long and is assigned to tpgt->tport_tpgt, which is defined as u16. This may cause an integer overflow when tpgt is greater than USHRT_MAX (65535). I haven't tried to trigger it myself, but it is possible to trigger it by calling usbg_make_tpg() with a large value for tpgt. I modified the type of tpgt to match tpgt->tport_tpgt and adjusted the relevant code accordingly. This patch is similar to commit 59c816c1f24d ("vhost/scsi: potential memory corruption"). Signed-off-by: Chen Yufeng Link: https://lore.kernel.org/r/20250415065857.1619-1-chenyufeng@iie.ac.cn Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

usb: gadget: f_tcm: Don't prepare BOT write request twice

2025-02-17T08:40:22+00:00

commit 94d9bf671ae314cacc2d7bf96bd233b4abc7cede upstream. The duplicate kmalloc here is causing memory leak. The request preparation in bot_send_write_request is also done in usbg_prepare_w_request. Remove the duplicate work. Fixes: c52661d60f63 ("usb-gadget: Initial merge of target module for UASP + BOT") Cc: stable@vger.kernel.org Signed-off-by: Thinh Nguyen Link: https://lore.kernel.org/r/f4f26c3d586cde0d46f8c3bcb4e8ae32311b650d.1733876548.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_tcm: ep_autoconfig with fullspeed endpoint

2025-02-17T08:40:22+00:00

commit 25224c1f07d31c261d04dfbc705a7a0f314a825d upstream. Match usb endpoint using fullspeed endpoint descriptor to make sure the wMaxPacketSize for fullspeed descriptors is automatically configured. Fixes: c52661d60f63 ("usb-gadget: Initial merge of target module for UASP + BOT") Cc: stable@vger.kernel.org Signed-off-by: Thinh Nguyen Link: https://lore.kernel.org/r/e4507bc824aed6e7c7f5a718392ab6a7c1480a7f.1733876548.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_tcm: Decrement command ref count on cleanup

2025-02-17T08:40:22+00:00

commit 3b2a52e88ab0c9469eaadd4d4c8f57d072477820 upstream. We submitted the command with TARGET_SCF_ACK_KREF, which requires acknowledgment of command completion. If the command fails, make sure to decrement the ref count. Fixes: cff834c16d23 ("usb-gadget/tcm: Convert to TARGET_SCF_ACK_KREF I/O krefs") Cc: stable@vger.kernel.org Signed-off-by: Thinh Nguyen Link: https://lore.kernel.org/r/3c667b4d9c8b0b580346a69ff53616b6a74cfea2.1733876548.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_tcm: Translate error to sense

2025-02-17T08:40:22+00:00

commit 98fa00fd3ae43b857b4976984a135483d89d9281 upstream. When respond with check_condition error status, clear from_transport input so the target layer can translate the sense reason reported by f_tcm. Fixes: c52661d60f63 ("usb-gadget: Initial merge of target module for UASP + BOT") Cc: stable@vger.kernel.org Signed-off-by: Thinh Nguyen Link: https://lore.kernel.org/r/b2a5577efe7abd0af0051229622cf7d3be5cdcd0.1733876548.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_tcm: Don't free command immediately

2025-02-08T08:52:38+00:00

commit c225d006a31949d673e646d585d9569bc28feeb9 upstream. Don't prematurely free the command. Wait for the status completion of the sense status. It can be freed then. Otherwise we will double-free the command. Fixes: cff834c16d23 ("usb-gadget/tcm: Convert to TARGET_SCF_ACK_KREF I/O krefs") Cc: stable@vger.kernel.org Signed-off-by: Thinh Nguyen Link: https://lore.kernel.org/r/ae919ac431f16275e05ec819bdffb3ac5f44cbe1.1733876548.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_tcm: Fix Get/SetInterface return value

2025-02-08T08:52:36+00:00

commit 3b997089903b909684114aca6f79d683e5c64a0e upstream. Check to make sure that the GetInterface and SetInterface are for valid interface. Return proper alternate setting number on GetInterface. Fixes: 0b8b1a1fede0 ("usb: gadget: f_tcm: Provide support to get alternate setting in tcm function") Cc: stable@vger.kernel.org Signed-off-by: Thinh Nguyen Link: https://lore.kernel.org/r/ffd91b4640945ea4d3b4f4091cf1abbdbd9cf4fc.1733876548.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman

Merge patch series "target: TMF and recovery fixes"

2023-03-24T21:39:15+00:00

Mike Christie says: The following patches apply over Martin's 6.4 branches and Linus's tree. They fix a couple regressions in iscsit that occur when there are TMRs executing and a connection is closed. It also includes Dimitry's fixes in related code paths for cmd cleanup when ERL2 is used and the write pending hang during conn cleanup. This version of the patchset brings it back to just regressions and fixes for bugs we have a lot of users hitting. I'm going to fix isert and get it hooked into iscsit properly in a second patchset, because this one was getting so large. I've also moved my cleanup type of patches for a 3rd patchset. Link: https://lore.kernel.org/r/20230319015620.96006-1-michael.christie@oracle.com Signed-off-by: Martin K. Petersen

scsi: target: Pass in cmd counter to use during cmd setup

2023-03-24T21:32:23+00:00

Allow target_get_sess_cmd() users to pass in the cmd counter they want to use. Right now we pass in the session's cmd counter but in a subsequent commit iSCSI will switch from per session to per conn. Signed-off-by: Mike Christie Link: https://lore.kernel.org/r/20230319015620.96006-4-michael.christie@oracle.com Signed-off-by: Martin K. Petersen