{"id":"CVE-2026-93168","aliases":[],"cve":{"records":[{"id":"CVE-2026-93168","source":"Linux","state":"PUBLISHED","reasons":[],"replacements":[],"disputed":false,"unsupportedWhenAssigned":false,"reserved":"2026-09-17T16:02:15.090Z","published":"2026-09-17T16:11:59.904Z","modified":"2026-10-30T12:36:12.039Z"}],"publishers":[{"name":"Linux","role":"CNA","organizationId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","modified":"2026-10-30T12:36:12.039Z"}],"references":[{"url":"https://git.kernel.org/stable/c/4237b5cc181a17f5a2a797655c1ce2c64e01c550","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/2ba67aa183a3ce174d534425b67eda84f6e3c896","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/c30a26d4987a01e619449bf170f584c007e07d75","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/f786e7b3adbf3bd14964a1cedf9d55b6ad91dcd7","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/8b5654d317277e6e505c23f8fa7e415237fefc7f","tags":[],"source":"Linux"},{"url":"https://git.kernel.org/stable/c/aa99c4d1d63bbc26a5fc4c667d89b2595743c19d","tags":[],"source":"Linux"}],"weaknesses":[],"applicability":[{"source":"Linux","statements":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"7.2.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.6","versionEndExcluding":"7.3"}]}]}]}],"prioritization":[]},"title":"dmaengine: xilinx_dma: Fix CPU stall in xilinx_dma_poll_timeout","titleSource":"Linux","descriptionSource":"Linux","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndmaengine: xilinx_dma: Fix CPU stall in xilinx_dma_poll_timeout\n\nCurrently when calling xilinx_dma_poll_timeout with delay_us=0 and a\ncondition that is never fulfilled, the CPU busy-waits for prolonged time\nand the timeout triggers only with a massive delay causing a CPU stall.\n\nThis happens due to a huge underestimation of wall clock time in\npoll_timeout_us_atomic. Commit 7349a69cf312 (\"iopoll: Do not use\ntimekeeping in read_poll_timeout_atomic()\") changed the behavior to no\nlonger use ktime_get at the expense of underestimation of wall clock\ntime which appears to be very large for delay_us=0. Instead of timing\nout after approximately XILINX_DMA_LOOP_COUNT microseconds, the timeout\ntakes XILINX_DMA_LOOP_COUNT * 1000 * (time that the overhead of the for\nloop in poll_timeout_us_atomic takes) which is in the range of several\nminutes for XILINX_DMA_LOOP_COUNT=1000000. Fix this by using a non-zero\nvalue for delay_us. Use delay_us=10 to keep the delay in the hot path of\nstarting DMA transfers minimal but still avoid CPU stalls in case of\nunexpected hardware failures.\n\nOne-off measurement with delay_us=0 causes the cpu to busy wait around 7\nminutes in the timeout case. After applying this patch with delay_us=10\nthe measured timeout was 1053428 microseconds which is roughly\nequivalent to the expected 1000000 microseconds specified in\nXILINX_DMA_LOOP_COUNT.\n\nAdd a constant XILINX_DMA_POLL_DELAY_US for delay_us value.","score":null,"severity":"unknown","published":"2026-09-17T16:11:59.904Z","modified":"2026-10-30T12:36:12.039Z","withdrawn":false,"knownExploited":false,"affected":[],"products":[{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"9495f2648287029fb5545c34a0fa318426ebe84c","status":"affected","lessThan":"4237b5cc181a17f5a2a797655c1ce2c64e01c550","versionType":"git"},{"version":"9495f2648287029fb5545c34a0fa318426ebe84c","status":"affected","lessThan":"2ba67aa183a3ce174d534425b67eda84f6e3c896","versionType":"git"},{"version":"9495f2648287029fb5545c34a0fa318426ebe84c","status":"affected","lessThan":"c30a26d4987a01e619449bf170f584c007e07d75","versionType":"git"},{"version":"9495f2648287029fb5545c34a0fa318426ebe84c","status":"affected","lessThan":"f786e7b3adbf3bd14964a1cedf9d55b6ad91dcd7","versionType":"git"},{"version":"9495f2648287029fb5545c34a0fa318426ebe84c","status":"affected","lessThan":"8b5654d317277e6e505c23f8fa7e415237fefc7f","versionType":"git"},{"version":"9495f2648287029fb5545c34a0fa318426ebe84c","status":"affected","lessThan":"aa99c4d1d63bbc26a5fc4c667d89b2595743c19d","versionType":"git"}],"defaultStatus":"unaffected","cpes":[],"source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-93168"},{"vendor":"Linux","name":"Linux","platforms":[],"versions":[{"version":"4.6","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.6","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.6","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"defaultStatus":"affected","cpes":[],"source":"Linux","url":"https://www.cve.org/CVERecord?id=CVE-2026-93168"}],"remediation":[],"references":["https://git.kernel.org/stable/c/4237b5cc181a17f5a2a797655c1ce2c64e01c550","https://git.kernel.org/stable/c/2ba67aa183a3ce174d534425b67eda84f6e3c896","https://git.kernel.org/stable/c/c30a26d4987a01e619449bf170f584c007e07d75","https://git.kernel.org/stable/c/f786e7b3adbf3bd14964a1cedf9d55b6ad91dcd7","https://git.kernel.org/stable/c/8b5654d317277e6e505c23f8fa7e415237fefc7f","https://git.kernel.org/stable/c/aa99c4d1d63bbc26a5fc4c667d89b2595743c19d"],"sources":[{"name":"CVE","id":"CVE-2026-93168","modified":"2026-10-30T12:36:12.039Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-93168"}],"assessments":[],"sourceAffected":[],"observedAt":"2026-10-30T13:55:17.298Z","kev":{"status":"not-listed","checkedAt":"2026-11-14T22:40:32.870Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[],"aiSummary":null}