{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-05-05T05:40:56.209","vulnerabilities":[{"cve":{"id":"CVE-2024-42305","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","published":"2024-08-17T09:15:10.690","lastModified":"2025-11-03T22:17:59.697","vulnStatus":"Modified","cveTags":[],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: check dot and dotdot of dx_root before making dir indexed\n\nSyzbot reports a issue as follows:\n============================================\nBUG: unable to handle page fault for address: ffffed11022e24fe\nPGD 23ffee067 P4D 23ffee067 PUD 0\nOops: Oops: 0000 [#1] PREEMPT SMP KASAN PTI\nCPU: 0 PID: 5079 Comm: syz-executor306 Not tainted 6.10.0-rc5-g55027e689933 #0\nCall Trace:\n <TASK>\n make_indexed_dir+0xdaf/0x13c0 fs/ext4/namei.c:2341\n ext4_add_entry+0x222a/0x25d0 fs/ext4/namei.c:2451\n ext4_rename fs/ext4/namei.c:3936 [inline]\n ext4_rename2+0x26e5/0x4370 fs/ext4/namei.c:4214\n[...]\n============================================\n\nThe immediate cause of this problem is that there is only one valid dentry\nfor the block to be split during do_split, so split==0 results in out of\nbounds accesses to the map triggering the issue.\n\n    do_split\n      unsigned split\n      dx_make_map\n       count = 1\n      split = count/2 = 0;\n      continued = hash2 == map[split - 1].hash;\n       ---> map[4294967295]\n\nThe maximum length of a filename is 255 and the minimum block size is 1024,\nso it is always guaranteed that the number of entries is greater than or\nequal to 2 when do_split() is called.\n\nBut syzbot's crafted image has no dot and dotdot in dir, and the dentry\ndistribution in dirblock is as follows:\n\n  bus     dentry1          hole           dentry2           free\n|xx--|xx-------------|...............|xx-------------|...............|\n0   12 (8+248)=256  268     256     524 (8+256)=264 788     236     1024\n\nSo when renaming dentry1 increases its name_len length by 1, neither hole\nnor free is sufficient to hold the new dentry, and make_indexed_dir() is\ncalled.\n\nIn make_indexed_dir() it is assumed that the first two entries of the\ndirblock must be dot and dotdot, so bus and dentry1 are left in dx_root\nbecause they are treated as dot and dotdot, and only dentry2 is moved\nto the new leaf block. That's why count is equal to 1.\n\nTherefore add the ext4_check_dx_root() helper function to add more sanity\nchecks to dot and dotdot before starting the conversion to avoid the above\nissue."},{"lang":"es","value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ext4: verifique el punto y el punto de dx_root antes de indexar el directorio Syzbot informa un problema de la siguiente manera: =================== ========================= ERROR: no se puede manejar el error de página para la dirección: ffffed11022e24fe PGD 23ffee067 P4D 23ffee067 PUD 0 Ups: Ups: 0000 [#1 ] PREEMPT SMP KASAN PTI CPU: 0 PID: 5079 Comm: syz-executor306 No contaminado 6.10.0-rc5-g55027e689933 #0 Seguimiento de llamada:  make_indexed_dir+0xdaf/0x13c0 fs/ext4/namei.c:2341 ext4_add_entry+0x222 un /0x25d0 fs/ext4/namei.c:2451 ext4_rename fs/ext4/namei.c:3936 [en línea] text4_rename2+0x26e5/0x4370 fs/ext4/namei.c:4214 [...] ======= ====================================== La causa inmediata de este problema es que sólo hay una válida dentry para que el bloque se divida durante do_split, por lo que split==0 da como resultado accesos fuera de los límites al mapa que desencadenan el problema. do_split división sin signo dx_make_map recuento = 1 división = recuento/2 = 0; continúa = hash2 == mapa[dividido - 1].hash; ---&gt; map[4294967295] La longitud máxima de un nombre de archivo es 255 y el tamaño mínimo de bloque es 1024, por lo que siempre se garantiza que el número de entradas sea mayor o igual a 2 cuando se llama a do_split(). Pero la imagen manipulada por syzbot no tiene punto ni puntopunto en el directorio, y la distribución de dentry en dirblock es la siguiente: bus dentry1 agujero dentry2 gratis |xx--|xx-------------|... ............|xx-------------|...............| 0 12 (8+248)=256 268 256 524 (8+256)=264 788 236 1024 Entonces, cuando se cambia el nombre de dentry1 se aumenta la longitud de name_len en 1, ni el agujero ni el espacio libre son suficientes para contener el nuevo dentry, y make_indexed_dir() es llamado. En make_indexed_dir() se supone que las dos primeras entradas del bloque de directorios deben ser punto y puntopunto, por lo que bus y dentry1 se dejan en dx_root porque se tratan como punto y puntodot, y solo dentry2 se mueve al nuevo bloque de hoja. Es por eso que el recuento es igual a 1. Por lo tanto, agregue la función auxiliar ext4_check_dx_root() para agregar más controles de cordura a los puntos y puntos antes de comenzar la conversión para evitar el problema anterior."}],"metrics":{"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.5,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":3.6}]},"weaknesses":[{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"CWE-125"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.20","versionEndExcluding":"4.19.320","matchCriteriaId":"1F2DB4BC-32AC-42D5-A39A-FF732AB5FC96"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.20","versionEndExcluding":"5.4.282","matchCriteriaId":"A8961D98-9ACF-4188-BA88-44038B14BC28"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.5","versionEndExcluding":"5.10.224","matchCriteriaId":"5CCEDF13-293D-4E64-B501-4409D0365AFE"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.15.165","matchCriteriaId":"B4E2B568-3171-41DE-B519-F2B1A3600D94"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16","versionEndExcluding":"6.1.103","matchCriteriaId":"E45EAC72-8329-4F99-8276-86AF9BB3496A"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.44","matchCriteriaId":"CC912330-6B41-4C6B-99AF-F3857FBACB6A"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.10.3","matchCriteriaId":"92D388F2-1EAF-4CFA-AC06-5B26D762EA7D"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:2.6.19:-:*:*:*:*:*:*","matchCriteriaId":"9E2DBD4C-9DD9-4DD3-87CB-A0070A789CEA"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:2.6.19:rc2:*:*:*:*:*:*","matchCriteriaId":"8D97ED16-D6B7-4445-889C-4D6DE2EDC49A"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:2.6.19:rc3:*:*:*:*:*:*","matchCriteriaId":"B2C2D5D4-9A4B-4CDF-8D71-D22EB5E97D5A"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:2.6.19:rc4:*:*:*:*:*:*","matchCriteriaId":"DFFB2843-A867-48EC-97D7-B106C7BBAED0"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:2.6.19:rc5:*:*:*:*:*:*","matchCriteriaId":"3CD3FE23-1A10-47E6-AD7E-D67F1BE3C5E2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:2.6.19:rc6:*:*:*:*:*:*","matchCriteriaId":"9F39FC76-7D77-4064-94D3-A16C436FA8D1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/19e13b4d7f0303186fcc891aba8d0de7c8fdbda8","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/42d420517072028fb0eb852c358056b7717ba5aa","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/50ea741def587a64e08879ce6c6a30131f7111e7","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/8afe06ed3be7a874b3cd82ef5f8959aca8d6429a","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/9d241b7a39af192d1bb422714a458982c7cc67a2","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/abb411ac991810c0bcbe51c2e76d2502bf611b5c","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/b80575ffa98b5bb3a5d4d392bfe4c2e03e9557db","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://git.kernel.org/stable/c/cdd345321699042ece4a9d2e70754d2397d378c5","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"]},{"url":"https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html","source":"af854a3a-2127-422b-91ae-364da2661108"}]}}]}