{ "containers": { "cna": { "providerMetadata": { "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvfs: Don't evict inode under the inode lru traversing context\n\nThe inode reclaiming process(See function prune_icache_sb) collects all\nreclaimable inodes and mark them with I_FREEING flag at first, at that\ntime, other processes will be stuck if they try getting these inodes\n(See function find_inode_fast), then the reclaiming process destroy the\ninodes by function dispose_list(). Some filesystems(eg. ext4 with\nea_inode feature, ubifs with xattr) may do inode lookup in the inode\nevicting callback function, if the inode lookup is operated under the\ninode lru traversing context, deadlock problems may happen.\n\nCase 1: In function ext4_evict_inode(), the ea inode lookup could happen\n if ea_inode feature is enabled, the lookup process will be stuck\n\tunder the evicting context like this:\n\n 1. File A has inode i_reg and an ea inode i_ea\n 2. getfattr(A, xattr_buf) // i_ea is added into lru // lru->i_ea\n 3. Then, following three processes running like this:\n\n PA PB\n echo 2 > /proc/sys/vm/drop_caches\n shrink_slab\n prune_dcache_sb\n // i_reg is added into lru, lru->i_ea->i_reg\n prune_icache_sb\n list_lru_walk_one\n inode_lru_isolate\n i_ea->i_state |= I_FREEING // set inode state\n inode_lru_isolate\n __iget(i_reg)\n spin_unlock(&i_reg->i_lock)\n spin_unlock(lru_lock)\n rm file A\n i_reg->nlink = 0\n iput(i_reg) // i_reg->nlink is 0, do evict\n ext4_evict_inode\n ext4_xattr_delete_inode\n ext4_xattr_inode_dec_ref_all\n ext4_xattr_inode_iget\n ext4_iget(i_ea->i_ino)\n iget_locked\n find_inode_fast\n __wait_on_freeing_inode(i_ea) ----→ AA deadlock\n dispose_list // cannot be executed by prune_icache_sb\n wake_up_bit(&i_ea->i_state)\n\nCase 2: In deleted inode writing function ubifs_jnl_write_inode(), file\n deleting process holds BASEHD's wbuf->io_mutex while getting the\n\txattr inode, which could race with inode reclaiming process(The\n reclaiming process could try locking BASEHD's wbuf->io_mutex in\n\tinode evicting function), then an ABBA deadlock problem would\n\thappen as following:\n\n 1. File A has inode ia and a xattr(with inode ixa), regular file B has\n inode ib and a xattr.\n 2. getfattr(A, xattr_buf) // ixa is added into lru // lru->ixa\n 3. Then, following three processes running like this:\n\n PA PB PC\n echo 2 > /proc/sys/vm/drop_caches\n shrink_slab\n prune_dcache_sb\n // ib and ia are added into lru, lru->ixa->ib->ia\n prune_icache_sb\n list_lru_walk_one\n inode_lru_isolate\n ixa->i_state |= I_FREEING // set inode state\n inode_lru_isolate\n __iget(ib)\n spin_unlock(&ib->i_lock)\n spin_unlock(lru_lock)\n rm file B\n ib->nlink = 0\n rm file A\n iput(ia)\n ubifs_evict_inode(ia)\n ubifs_jnl_delete_inode(ia)\n ubifs_jnl_write_inode(ia)\n make_reservation(BASEHD) // Lock wbuf->io_mutex\n ubifs_iget(ixa->i_ino)\n iget_locked\n find_inode_fast\n __wait_on_freeing_inode(ixa)\n | iput(ib) // ib->nlink is 0, do evict\n | ubifs_evict_inode\n | ubifs_jnl_delete_inode(ib)\n ↓ ubifs_jnl_write_inode\n ABBA deadlock ←-----make_reservation(BASEHD)\n dispose_list // cannot be executed by prune_icache_sb\n wake_up_bit(&ixa->i_state)\n\nFix the possible deadlock by using new inode state flag I_LRU_ISOLATING\nto pin the inode in memory while inode_lru_isolate(\n---truncated---" } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/inode.c", "include/linux/fs.h" ], "versions": [ { "version": "e50e5129f384", "lessThan": "3525ad25240d", "status": "affected", "versionType": "git" }, { "version": "e50e5129f384", "lessThan": "03880af02a78", "status": "affected", "versionType": "git" }, { "version": "e50e5129f384", "lessThan": "cda54ec82c0f", "status": "affected", "versionType": "git" }, { "version": "e50e5129f384", "lessThan": "437741eba63b", "status": "affected", "versionType": "git" }, { "version": "e50e5129f384", "lessThan": "b9bda5f6012d", "status": "affected", "versionType": "git" }, { "version": "e50e5129f384", "lessThan": "9063ab49c11e", "status": "affected", "versionType": "git" }, { "version": "e50e5129f384", "lessThan": "2a0629834cd8", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/inode.c", "include/linux/fs.h" ], "versions": [ { "version": "4.13", "status": "affected" }, { "version": "0", "lessThan": "4.13", "status": "unaffected", "versionType": "custom" }, { "version": "5.4.283", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.10.225", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "custom" }, { "version": "5.15.166", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.1.107", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.6.48", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.10.7", "lessThanOrEqual": "6.10.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.11", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3525ad25240dfdd8c78f3470911ed10aa727aa72" }, { "url": "https://git.kernel.org/stable/c/03880af02a78bc9a98b5a581f529cf709c88a9b8" }, { "url": "https://git.kernel.org/stable/c/cda54ec82c0f9d05393242b20b13f69b083f7e88" }, { "url": "https://git.kernel.org/stable/c/437741eba63bf4e437e2beb5583f8633556a2b98" }, { "url": "https://git.kernel.org/stable/c/b9bda5f6012dd00372f3a06a82ed8971a4c57c32" }, { "url": "https://git.kernel.org/stable/c/9063ab49c11e9518a3f2352434bb276cc8134c5f" }, { "url": "https://git.kernel.org/stable/c/2a0629834cd82f05d424bbc193374f9a43d1f87d" } ], "title": "vfs: Don't evict inode under the inode lru traversing context", "x_generator": { "engine": "bippy-c9c4e1df01b2" } } }, "cveMetadata": { "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038", "cveID": "CVE-2024-45003", "requesterUserId": "gregkh@kernel.org", "serial": "1", "state": "PUBLISHED" }, "dataType": "CVE_RECORD", "dataVersion": "5.0" }