{"api_version":"1","generated_at":"2026-05-28T03:14:29+00:00","cve":"CVE-2026-46052","urls":{"html":"https://cve.report/CVE-2026-46052","api":"https://cve.report/api/cve/CVE-2026-46052.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-46052","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-46052"},"summary":{"title":"ceph: only d_add() negative dentries when they are unhashed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: only d_add() negative dentries when they are unhashed\n\nCeph can call d_add(dentry, NULL) on a negative dentry that is already\npresent in the primary dcache hash.\n\nIn the current VFS that is not safe.  d_add() goes through __d_add()\nto __d_rehash(), which unconditionally reinserts dentry->d_hash into\nthe hlist_bl bucket.  If the dentry is already hashed, reinserting the\nsame node can corrupt the bucket, including creating a self-loop.\nOnce that happens, __d_lookup() can spin forever in the hlist_bl walk,\ntypically looping only on the d_name.hash mismatch check and\neventually triggering RCU stall reports like this one:\n\n rcu: INFO: rcu_sched self-detected stall on CPU\n rcu:         87-....: (2100 ticks this GP) idle=3a4c/1/0x4000000000000000 softirq=25003319/25003319 fqs=829\n rcu:         (t=2101 jiffies g=79058445 q=698988 ncpus=192)\n CPU: 87 UID: 2952868916 PID: 3933303 Comm: php-cgi8.3 Not tainted 6.18.17-i1-amd #950 NONE\n Hardware name: Dell Inc. PowerEdge R7615/0G9DHV, BIOS 1.6.6 09/22/2023\n RIP: 0010:__d_lookup+0x46/0xb0\n Code: c1 e8 07 48 8d 04 c2 48 8b 00 49 89 fc 49 89 f5 48 89 c3 48 83 e3 fe 48 83 f8 01 77 0f eb 2d 0f 1f 44 00 00 48 8b 1b 48 85 db <74> 20 39 6b 18 75 f3 48 8d 7b 78 e8 ba 85 d0 00 4c 39 63 10 74 1f\n RSP: 0018:ff745a70c8253898 EFLAGS: 00000282\n RAX: ff26e470054cb208 RBX: ff26e470054cb208 RCX: 000000006e958966\n RDX: ff26e48267340000 RSI: ff745a70c82539b0 RDI: ff26e458f74655c0\n RBP: 000000006e958966 R08: 0000000000000180 R09: 9cd08d909b919a89\n R10: ff26e458f74655c0 R11: 0000000000000000 R12: ff26e458f74655c0\n R13: ff745a70c82539b0 R14: d0d0d0d0d0d0d0d0 R15: 2f2f2f2f2f2f2f2f\n FS:  00007f5770896980(0000) GS:ff26e482c5d88000(0000) knlGS:0000000000000000\n CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f5764de50c0 CR3: 000000a72abb5001 CR4: 0000000000771ef0\n PKRU: 55555554\n Call Trace:\n  <TASK>\n  lookup_fast+0x9f/0x100\n  walk_component+0x1f/0x150\n  link_path_walk+0x20e/0x3d0\n  path_lookupat+0x68/0x180\n  filename_lookup+0xdc/0x1e0\n  vfs_statx+0x6c/0x140\n  vfs_fstatat+0x67/0xa0\n  __do_sys_newfstatat+0x24/0x60\n  do_syscall_64+0x6a/0x230\n  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nThis is reachable with reused cached negative dentries.  A Ceph lookup\nor atomic_open can be handed a negative dentry that is already hashed,\nand fs/ceph/dir.c then hits one of two paths that incorrectly assume\n\"negative\" also means \"unhashed\":\n\n  - ceph_finish_lookup():\n      MDS reply is -ENOENT with no trace\n      -> d_add(dentry, NULL)\n\n  - ceph_lookup():\n      local ENOENT fast path for a complete directory with shared caps\n      -> d_add(dentry, NULL)\n\nBoth paths can therefore re-add an already-hashed negative dentry.\n\nCeph already uses the correct pattern elsewhere: ceph_fill_trace() only\ncalls d_add(dn, NULL) for a negative null-dentry reply when d_unhashed(dn)\nis true.\n\nFix both fs/ceph/dir.c sites the same way: only call d_add() for a\nnegative dentry when it is actually unhashed.  If the negative dentry\nis already hashed, leave it in place and reuse it as-is.\n\nThis preserves the existing behavior for unhashed dentries while\navoiding d_hash list corruption for reused hashed negatives.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-27 14:17:24","updated_at":"2026-05-27 14:48:03"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/4179cc390dacebc87079419ec92f86f3dc46294d","name":"https://git.kernel.org/stable/c/4179cc390dacebc87079419ec92f86f3dc46294d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2010cb06b9df7d3c816c78358c566bdacbdf38ff","name":"https://git.kernel.org/stable/c/2010cb06b9df7d3c816c78358c566bdacbdf38ff","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/803447f93d75ab6e40c85e6d12b5630d281d70d6","name":"https://git.kernel.org/stable/c/803447f93d75ab6e40c85e6d12b5630d281d70d6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b91e535f208c48a5e7464f1aa38338a30e7912df","name":"https://git.kernel.org/stable/c/b91e535f208c48a5e7464f1aa38338a30e7912df","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/83ce43a21bb7df8dd52228afdd918d2d058eefde","name":"https://git.kernel.org/stable/c/83ce43a21bb7df8dd52228afdd918d2d058eefde","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-46052","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46052","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2817b000b02c5f0c05af67c01fb2684e1381d6ef 83ce43a21bb7df8dd52228afdd918d2d058eefde git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2817b000b02c5f0c05af67c01fb2684e1381d6ef 4179cc390dacebc87079419ec92f86f3dc46294d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2817b000b02c5f0c05af67c01fb2684e1381d6ef b91e535f208c48a5e7464f1aa38338a30e7912df git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2817b000b02c5f0c05af67c01fb2684e1381d6ef 2010cb06b9df7d3c816c78358c566bdacbdf38ff git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2817b000b02c5f0c05af67c01fb2684e1381d6ef 803447f93d75ab6e40c85e6d12b5630d281d70d6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2.6.34","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 2.6.34 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.140 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.86 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.27 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.4 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/ceph/dir.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"83ce43a21bb7df8dd52228afdd918d2d058eefde","status":"affected","version":"2817b000b02c5f0c05af67c01fb2684e1381d6ef","versionType":"git"},{"lessThan":"4179cc390dacebc87079419ec92f86f3dc46294d","status":"affected","version":"2817b000b02c5f0c05af67c01fb2684e1381d6ef","versionType":"git"},{"lessThan":"b91e535f208c48a5e7464f1aa38338a30e7912df","status":"affected","version":"2817b000b02c5f0c05af67c01fb2684e1381d6ef","versionType":"git"},{"lessThan":"2010cb06b9df7d3c816c78358c566bdacbdf38ff","status":"affected","version":"2817b000b02c5f0c05af67c01fb2684e1381d6ef","versionType":"git"},{"lessThan":"803447f93d75ab6e40c85e6d12b5630d281d70d6","status":"affected","version":"2817b000b02c5f0c05af67c01fb2684e1381d6ef","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/ceph/dir.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.34"},{"lessThan":"2.6.34","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.140","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.86","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.27","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.140","versionStartIncluding":"2.6.34","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.86","versionStartIncluding":"2.6.34","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.27","versionStartIncluding":"2.6.34","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.4","versionStartIncluding":"2.6.34","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1-rc1","versionStartIncluding":"2.6.34","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: only d_add() negative dentries when they are unhashed\n\nCeph can call d_add(dentry, NULL) on a negative dentry that is already\npresent in the primary dcache hash.\n\nIn the current VFS that is not safe.  d_add() goes through __d_add()\nto __d_rehash(), which unconditionally reinserts dentry->d_hash into\nthe hlist_bl bucket.  If the dentry is already hashed, reinserting the\nsame node can corrupt the bucket, including creating a self-loop.\nOnce that happens, __d_lookup() can spin forever in the hlist_bl walk,\ntypically looping only on the d_name.hash mismatch check and\neventually triggering RCU stall reports like this one:\n\n rcu: INFO: rcu_sched self-detected stall on CPU\n rcu:         87-....: (2100 ticks this GP) idle=3a4c/1/0x4000000000000000 softirq=25003319/25003319 fqs=829\n rcu:         (t=2101 jiffies g=79058445 q=698988 ncpus=192)\n CPU: 87 UID: 2952868916 PID: 3933303 Comm: php-cgi8.3 Not tainted 6.18.17-i1-amd #950 NONE\n Hardware name: Dell Inc. PowerEdge R7615/0G9DHV, BIOS 1.6.6 09/22/2023\n RIP: 0010:__d_lookup+0x46/0xb0\n Code: c1 e8 07 48 8d 04 c2 48 8b 00 49 89 fc 49 89 f5 48 89 c3 48 83 e3 fe 48 83 f8 01 77 0f eb 2d 0f 1f 44 00 00 48 8b 1b 48 85 db <74> 20 39 6b 18 75 f3 48 8d 7b 78 e8 ba 85 d0 00 4c 39 63 10 74 1f\n RSP: 0018:ff745a70c8253898 EFLAGS: 00000282\n RAX: ff26e470054cb208 RBX: ff26e470054cb208 RCX: 000000006e958966\n RDX: ff26e48267340000 RSI: ff745a70c82539b0 RDI: ff26e458f74655c0\n RBP: 000000006e958966 R08: 0000000000000180 R09: 9cd08d909b919a89\n R10: ff26e458f74655c0 R11: 0000000000000000 R12: ff26e458f74655c0\n R13: ff745a70c82539b0 R14: d0d0d0d0d0d0d0d0 R15: 2f2f2f2f2f2f2f2f\n FS:  00007f5770896980(0000) GS:ff26e482c5d88000(0000) knlGS:0000000000000000\n CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f5764de50c0 CR3: 000000a72abb5001 CR4: 0000000000771ef0\n PKRU: 55555554\n Call Trace:\n  <TASK>\n  lookup_fast+0x9f/0x100\n  walk_component+0x1f/0x150\n  link_path_walk+0x20e/0x3d0\n  path_lookupat+0x68/0x180\n  filename_lookup+0xdc/0x1e0\n  vfs_statx+0x6c/0x140\n  vfs_fstatat+0x67/0xa0\n  __do_sys_newfstatat+0x24/0x60\n  do_syscall_64+0x6a/0x230\n  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nThis is reachable with reused cached negative dentries.  A Ceph lookup\nor atomic_open can be handed a negative dentry that is already hashed,\nand fs/ceph/dir.c then hits one of two paths that incorrectly assume\n\"negative\" also means \"unhashed\":\n\n  - ceph_finish_lookup():\n      MDS reply is -ENOENT with no trace\n      -> d_add(dentry, NULL)\n\n  - ceph_lookup():\n      local ENOENT fast path for a complete directory with shared caps\n      -> d_add(dentry, NULL)\n\nBoth paths can therefore re-add an already-hashed negative dentry.\n\nCeph already uses the correct pattern elsewhere: ceph_fill_trace() only\ncalls d_add(dn, NULL) for a negative null-dentry reply when d_unhashed(dn)\nis true.\n\nFix both fs/ceph/dir.c sites the same way: only call d_add() for a\nnegative dentry when it is actually unhashed.  If the negative dentry\nis already hashed, leave it in place and reuse it as-is.\n\nThis preserves the existing behavior for unhashed dentries while\navoiding d_hash list corruption for reused hashed negatives."}],"providerMetadata":{"dateUpdated":"2026-05-27T12:57:10.777Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/83ce43a21bb7df8dd52228afdd918d2d058eefde"},{"url":"https://git.kernel.org/stable/c/4179cc390dacebc87079419ec92f86f3dc46294d"},{"url":"https://git.kernel.org/stable/c/b91e535f208c48a5e7464f1aa38338a30e7912df"},{"url":"https://git.kernel.org/stable/c/2010cb06b9df7d3c816c78358c566bdacbdf38ff"},{"url":"https://git.kernel.org/stable/c/803447f93d75ab6e40c85e6d12b5630d281d70d6"}],"title":"ceph: only d_add() negative dentries when they are unhashed","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-46052","datePublished":"2026-05-27T12:57:10.777Z","dateReserved":"2026-05-13T15:03:33.094Z","dateUpdated":"2026-05-27T12:57:10.777Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-27 14:17:24","lastModifiedDate":"2026-05-27 14:48:03","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"46052","Ordinal":"1","Title":"ceph: only d_add() negative dentries when they are unhashed","CVE":"CVE-2026-46052","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"46052","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nceph: only d_add() negative dentries when they are unhashed\n\nCeph can call d_add(dentry, NULL) on a negative dentry that is already\npresent in the primary dcache hash.\n\nIn the current VFS that is not safe.  d_add() goes through __d_add()\nto __d_rehash(), which unconditionally reinserts dentry->d_hash into\nthe hlist_bl bucket.  If the dentry is already hashed, reinserting the\nsame node can corrupt the bucket, including creating a self-loop.\nOnce that happens, __d_lookup() can spin forever in the hlist_bl walk,\ntypically looping only on the d_name.hash mismatch check and\neventually triggering RCU stall reports like this one:\n\n rcu: INFO: rcu_sched self-detected stall on CPU\n rcu:         87-....: (2100 ticks this GP) idle=3a4c/1/0x4000000000000000 softirq=25003319/25003319 fqs=829\n rcu:         (t=2101 jiffies g=79058445 q=698988 ncpus=192)\n CPU: 87 UID: 2952868916 PID: 3933303 Comm: php-cgi8.3 Not tainted 6.18.17-i1-amd #950 NONE\n Hardware name: Dell Inc. PowerEdge R7615/0G9DHV, BIOS 1.6.6 09/22/2023\n RIP: 0010:__d_lookup+0x46/0xb0\n Code: c1 e8 07 48 8d 04 c2 48 8b 00 49 89 fc 49 89 f5 48 89 c3 48 83 e3 fe 48 83 f8 01 77 0f eb 2d 0f 1f 44 00 00 48 8b 1b 48 85 db <74> 20 39 6b 18 75 f3 48 8d 7b 78 e8 ba 85 d0 00 4c 39 63 10 74 1f\n RSP: 0018:ff745a70c8253898 EFLAGS: 00000282\n RAX: ff26e470054cb208 RBX: ff26e470054cb208 RCX: 000000006e958966\n RDX: ff26e48267340000 RSI: ff745a70c82539b0 RDI: ff26e458f74655c0\n RBP: 000000006e958966 R08: 0000000000000180 R09: 9cd08d909b919a89\n R10: ff26e458f74655c0 R11: 0000000000000000 R12: ff26e458f74655c0\n R13: ff745a70c82539b0 R14: d0d0d0d0d0d0d0d0 R15: 2f2f2f2f2f2f2f2f\n FS:  00007f5770896980(0000) GS:ff26e482c5d88000(0000) knlGS:0000000000000000\n CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f5764de50c0 CR3: 000000a72abb5001 CR4: 0000000000771ef0\n PKRU: 55555554\n Call Trace:\n  <TASK>\n  lookup_fast+0x9f/0x100\n  walk_component+0x1f/0x150\n  link_path_walk+0x20e/0x3d0\n  path_lookupat+0x68/0x180\n  filename_lookup+0xdc/0x1e0\n  vfs_statx+0x6c/0x140\n  vfs_fstatat+0x67/0xa0\n  __do_sys_newfstatat+0x24/0x60\n  do_syscall_64+0x6a/0x230\n  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nThis is reachable with reused cached negative dentries.  A Ceph lookup\nor atomic_open can be handed a negative dentry that is already hashed,\nand fs/ceph/dir.c then hits one of two paths that incorrectly assume\n\"negative\" also means \"unhashed\":\n\n  - ceph_finish_lookup():\n      MDS reply is -ENOENT with no trace\n      -> d_add(dentry, NULL)\n\n  - ceph_lookup():\n      local ENOENT fast path for a complete directory with shared caps\n      -> d_add(dentry, NULL)\n\nBoth paths can therefore re-add an already-hashed negative dentry.\n\nCeph already uses the correct pattern elsewhere: ceph_fill_trace() only\ncalls d_add(dn, NULL) for a negative null-dentry reply when d_unhashed(dn)\nis true.\n\nFix both fs/ceph/dir.c sites the same way: only call d_add() for a\nnegative dentry when it is actually unhashed.  If the negative dentry\nis already hashed, leave it in place and reuse it as-is.\n\nThis preserves the existing behavior for unhashed dentries while\navoiding d_hash list corruption for reused hashed negatives.","Type":"Description","Title":"ceph: only d_add() negative dentries when they are unhashed"}]}}}