{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2024-56788","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-12-29T11:26:39.770Z","datePublished":"2025-01-11T12:35:47.985Z","dateUpdated":"2025-05-04T10:04:45.630Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2025-05-04T10:04:45.630Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: ethernet: oa_tc6: fix tx skb race condition between reference pointers\n\nThere are two skb pointers to manage tx skb's enqueued from n/w stack.\nwaiting_tx_skb pointer points to the tx skb which needs to be processed\nand ongoing_tx_skb pointer points to the tx skb which is being processed.\n\nSPI thread prepares the tx data chunks from the tx skb pointed by the\nongoing_tx_skb pointer. When the tx skb pointed by the ongoing_tx_skb is\nprocessed, the tx skb pointed by the waiting_tx_skb is assigned to\nongoing_tx_skb and the waiting_tx_skb pointer is assigned with NULL.\nWhenever there is a new tx skb from n/w stack, it will be assigned to\nwaiting_tx_skb pointer if it is NULL. Enqueuing and processing of a tx skb\nhandled in two different threads.\n\nConsider a scenario where the SPI thread processed an ongoing_tx_skb and\nit moves next tx skb from waiting_tx_skb pointer to ongoing_tx_skb pointer\nwithout doing any NULL check. At this time, if the waiting_tx_skb pointer\nis NULL then ongoing_tx_skb pointer is also assigned with NULL. After\nthat, if a new tx skb is assigned to waiting_tx_skb pointer by the n/w\nstack and there is a chance to overwrite the tx skb pointer with NULL in\nthe SPI thread. Finally one of the tx skb will be left as unhandled,\nresulting packet missing and memory leak.\n\n- Consider the below scenario where the TXC reported from the previous\ntransfer is 10 and ongoing_tx_skb holds an tx ethernet frame which can be\ntransported in 20 TXCs and waiting_tx_skb is still NULL.\n\ttx_credits = 10; /* 21 are filled in the previous transfer */\n\tongoing_tx_skb = 20;\n\twaiting_tx_skb = NULL; /* Still NULL */\n- So, (tc6->ongoing_tx_skb || tc6->waiting_tx_skb) becomes true.\n- After oa_tc6_prepare_spi_tx_buf_for_tx_skbs()\n\tongoing_tx_skb = 10;\n\twaiting_tx_skb = NULL; /* Still NULL */\n- Perform SPI transfer.\n- Process SPI rx buffer to get the TXC from footers.\n- Now let's assume previously filled 21 TXCs are freed so we are good to\ntransport the next remaining 10 tx chunks from ongoing_tx_skb.\n\ttx_credits = 21;\n\tongoing_tx_skb = 10;\n\twaiting_tx_skb = NULL;\n- So, (tc6->ongoing_tx_skb || tc6->waiting_tx_skb) becomes true again.\n- In the oa_tc6_prepare_spi_tx_buf_for_tx_skbs()\n\tongoing_tx_skb = NULL;\n\twaiting_tx_skb = NULL;\n\n- Now the below bad case might happen,\n\nThread1 (oa_tc6_start_xmit)\tThread2 (oa_tc6_spi_thread_handler)\n---------------------------\t-----------------------------------\n- if waiting_tx_skb is NULL\n\t\t\t\t- if ongoing_tx_skb is NULL\n\t\t\t\t- ongoing_tx_skb = waiting_tx_skb\n- waiting_tx_skb = skb\n\t\t\t\t- waiting_tx_skb = NULL\n\t\t\t\t...\n\t\t\t\t- ongoing_tx_skb = NULL\n- if waiting_tx_skb is NULL\n- waiting_tx_skb = skb\n\nTo overcome the above issue, protect the moving of tx skb reference from\nwaiting_tx_skb pointer to ongoing_tx_skb pointer and assigning new tx skb\nto waiting_tx_skb pointer, so that the other thread can't access the\nwaiting_tx_skb pointer until the current thread completes moving the tx\nskb reference safely."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/oa_tc6.c"],"versions":[{"version":"53fbde8ab21e8c2c6187159cc17fc10cbf20900a","lessThan":"1f2eb6c32bae04b375bb7a0aedbeefb6dbbcb775","status":"affected","versionType":"git"},{"version":"53fbde8ab21e8c2c6187159cc17fc10cbf20900a","lessThan":"e592b5110b3e9393881b0a019d86832bbf71a47f","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/oa_tc6.c"],"versions":[{"version":"6.12","status":"affected"},{"version":"0","lessThan":"6.12","status":"unaffected","versionType":"semver"},{"version":"6.12.7","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.13","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12","versionEndExcluding":"6.12.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12","versionEndExcluding":"6.13"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/1f2eb6c32bae04b375bb7a0aedbeefb6dbbcb775"},{"url":"https://git.kernel.org/stable/c/e592b5110b3e9393881b0a019d86832bbf71a47f"}],"title":"net: ethernet: oa_tc6: fix tx skb race condition between reference pointers","x_generator":{"engine":"bippy-1.2.0"}}}}