{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2022-49272","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-02-26T01:49:39.297Z","datePublished":"2025-02-26T01:56:18.626Z","dateUpdated":"2025-05-04T08:33:54.705Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2025-05-04T08:33:54.705Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock\n\nsyzbot caught a potential deadlock between the PCM\nruntime->buffer_mutex and the mm->mmap_lock.  It was brought by the\nrecent fix to cover the racy read/write and other ioctls, and in that\ncommit, I overlooked a (hopefully only) corner case that may take the\nrevert lock, namely, the OSS mmap.  The OSS mmap operation\nexceptionally allows to re-configure the parameters inside the OSS\nmmap syscall, where mm->mmap_mutex is already held.  Meanwhile, the\ncopy_from/to_user calls at read/write operations also take the\nmm->mmap_lock internally, hence it may lead to a AB/BA deadlock.\n\nA similar problem was already seen in the past and we fixed it with a\nrefcount (in commit b248371628aa).  The former fix covered only the\ncall paths with OSS read/write and OSS ioctls, while we need to cover\nthe concurrent access via both ALSA and OSS APIs now.\n\nThis patch addresses the problem above by replacing the buffer_mutex\nlock in the read/write operations with a refcount similar as we've\nused for OSS.  The new field, runtime->buffer_accessing, keeps the\nnumber of concurrent read/write operations.  Unlike the former\nbuffer_mutex protection, this protects only around the\ncopy_from/to_user() calls; the other codes are basically protected by\nthe PCM stream lock.  The refcount can be a negative, meaning blocked\nby the ioctls.  If a negative value is seen, the read/write aborts\nwith -EBUSY.  In the ioctl side, OTOH, they check this refcount, too,\nand set to a negative value for blocking unless it's already being\naccessed."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/sound/pcm.h","sound/core/pcm.c","sound/core/pcm_lib.c","sound/core/pcm_native.c"],"versions":[{"version":"73867cb2bc7dfa7fbd219e53a0b68d253d8fda09","lessThan":"7e9133607e1501c94881be35e118d8f84d96dcb4","status":"affected","versionType":"git"},{"version":"b3830197aa7413c65767cf5a1aa8775c83f0dbf7","lessThan":"40f4cffbe13a51faf136faf5f9ef6847782cd595","status":"affected","versionType":"git"},{"version":"08d1807f097a63ea00a7067dad89c1c81cb2115e","lessThan":"9661bf674d6a82b76e4ae424438a8ce1e3ed855d","status":"affected","versionType":"git"},{"version":"8527c8f052fb42091c6569cb928e472376a4a889","lessThan":"9017201e8d8c6d1472273361389ed431188584a0","status":"affected","versionType":"git"},{"version":"47711ff10c7e126702cfa725f6d86ef529d15a5f","lessThan":"7777744e92a0b30e3e0cce2758d911837011ebd9","status":"affected","versionType":"git"},{"version":"4d1b0ace2d56dc27cc4921eda7fae57f77f03eb5","lessThan":"abedf0d08c79d76da0d6fa0d5dbbc98871dcbc2e","status":"affected","versionType":"git"},{"version":"dd2f8c684da3e226e5ec7a81c89ff5fd4a957a03","lessThan":"be9813ad2fc8f0885f5ce6925af0d993ce5da4e5","status":"affected","versionType":"git"},{"version":"dca947d4d26dbf925a64a6cfb2ddbc035e831a3d","lessThan":"bc55cfd5718c7c23e5524582e9fa70b4d10f2433","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/sound/pcm.h","sound/core/pcm.c","sound/core/pcm_lib.c","sound/core/pcm_native.c"],"versions":[{"version":"5.10.109","lessThan":"5.10.110","status":"affected","versionType":"semver"},{"version":"5.15.32","lessThan":"5.15.33","status":"affected","versionType":"semver"},{"version":"5.16.18","lessThan":"5.16.19","status":"affected","versionType":"semver"},{"version":"5.17.1","lessThan":"5.17.2","status":"affected","versionType":"semver"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.109","versionEndExcluding":"5.10.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.32","versionEndExcluding":"5.15.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16.18","versionEndExcluding":"5.16.19"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17.1","versionEndExcluding":"5.17.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/7e9133607e1501c94881be35e118d8f84d96dcb4"},{"url":"https://git.kernel.org/stable/c/40f4cffbe13a51faf136faf5f9ef6847782cd595"},{"url":"https://git.kernel.org/stable/c/9661bf674d6a82b76e4ae424438a8ce1e3ed855d"},{"url":"https://git.kernel.org/stable/c/9017201e8d8c6d1472273361389ed431188584a0"},{"url":"https://git.kernel.org/stable/c/7777744e92a0b30e3e0cce2758d911837011ebd9"},{"url":"https://git.kernel.org/stable/c/abedf0d08c79d76da0d6fa0d5dbbc98871dcbc2e"},{"url":"https://git.kernel.org/stable/c/be9813ad2fc8f0885f5ce6925af0d993ce5da4e5"},{"url":"https://git.kernel.org/stable/c/bc55cfd5718c7c23e5524582e9fa70b4d10f2433"}],"title":"ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock","x_generator":{"engine":"bippy-1.2.0"}}}}