{ "data_version": "4.0", "data_type": "CVE", "data_format": "MITRE", "CVE_data_meta": { "ID": "CVE-2024-27031", "ASSIGNER": "cve@kernel.org", "STATE": "PUBLIC" }, "description": { "description_data": [ { "lang": "eng", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFS: Fix nfs_netfs_issue_read() xarray locking for writeback interrupt\n\nThe loop inside nfs_netfs_issue_read() currently does not disable\ninterrupts while iterating through pages in the xarray to submit\nfor NFS read. This is not safe though since after taking xa_lock,\nanother page in the mapping could be processed for writeback inside\nan interrupt, and deadlock can occur. The fix is simple and clean\nif we use xa_for_each_range(), which handles the iteration with RCU\nwhile reducing code complexity.\n\nThe problem is easily reproduced with the following test:\n mount -o vers=3,fsc 127.0.0.1:/export /mnt/nfs\n dd if=/dev/zero of=/mnt/nfs/file1.bin bs=4096 count=1\n echo 3 > /proc/sys/vm/drop_caches\n dd if=/mnt/nfs/file1.bin of=/dev/null\n umount /mnt/nfs\n\nOn the console with a lockdep-enabled kernel a message similar to\nthe following will be seen:\n\n ================================\n WARNING: inconsistent lock state\n 6.7.0-lockdbg+ #10 Not tainted\n --------------------------------\n inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.\n test5/1708 [HC0[0]:SC0[0]:HE1:SE1] takes:\n ffff888127baa598 (&xa->xa_lock#4){+.?.}-{3:3}, at:\nnfs_netfs_issue_read+0x1b2/0x4b0 [nfs]\n {IN-SOFTIRQ-W} state was registered at:\n lock_acquire+0x144/0x380\n _raw_spin_lock_irqsave+0x4e/0xa0\n __folio_end_writeback+0x17e/0x5c0\n folio_end_writeback+0x93/0x1b0\n iomap_finish_ioend+0xeb/0x6a0\n blk_update_request+0x204/0x7f0\n blk_mq_end_request+0x30/0x1c0\n blk_complete_reqs+0x7e/0xa0\n __do_softirq+0x113/0x544\n __irq_exit_rcu+0xfe/0x120\n irq_exit_rcu+0xe/0x20\n sysvec_call_function_single+0x6f/0x90\n asm_sysvec_call_function_single+0x1a/0x20\n pv_native_safe_halt+0xf/0x20\n default_idle+0x9/0x20\n default_idle_call+0x67/0xa0\n do_idle+0x2b5/0x300\n cpu_startup_entry+0x34/0x40\n start_secondary+0x19d/0x1c0\n secondary_startup_64_no_verify+0x18f/0x19b\n irq event stamp: 176891\n hardirqs last enabled at (176891): []\n_raw_spin_unlock_irqrestore+0x44/0x60\n hardirqs last disabled at (176890): []\n_raw_spin_lock_irqsave+0x79/0xa0\n softirqs last enabled at (176646): []\n__irq_exit_rcu+0xfe/0x120\n softirqs last disabled at (176633): []\n__irq_exit_rcu+0xfe/0x120\n\n other info that might help us debug this:\n Possible unsafe locking scenario:\n\n CPU0\n ----\n lock(&xa->xa_lock#4);\n \n lock(&xa->xa_lock#4);\n\n *** DEADLOCK ***\n\n 2 locks held by test5/1708:\n #0: ffff888127baa498 (&sb->s_type->i_mutex_key#22){++++}-{4:4}, at:\n nfs_start_io_read+0x28/0x90 [nfs]\n #1: ffff888127baa650 (mapping.invalidate_lock#3){.+.+}-{4:4}, at:\n page_cache_ra_unbounded+0xa4/0x280\n\n stack backtrace:\n CPU: 6 PID: 1708 Comm: test5 Kdump: loaded Not tainted 6.7.0-lockdbg+\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-1.fc39\n04/01/2014\n Call Trace:\n dump_stack_lvl+0x5b/0x90\n mark_lock+0xb3f/0xd20\n __lock_acquire+0x77b/0x3360\n _raw_spin_lock+0x34/0x80\n nfs_netfs_issue_read+0x1b2/0x4b0 [nfs]\n netfs_begin_read+0x77f/0x980 [netfs]\n nfs_netfs_readahead+0x45/0x60 [nfs]\n nfs_readahead+0x323/0x5a0 [nfs]\n read_pages+0xf3/0x5c0\n page_cache_ra_unbounded+0x1c8/0x280\n filemap_get_pages+0x38c/0xae0\n filemap_read+0x206/0x5e0\n nfs_file_read+0xb7/0x140 [nfs]\n vfs_read+0x2a9/0x460\n ksys_read+0xb7/0x140" } ] }, "problemtype": { "problemtype_data": [ { "description": [ { "lang": "eng", "value": "n/a" } ] } ] }, "affects": { "vendor": { "vendor_data": [ { "vendor_name": "Linux", "product": { "product_data": [ { "product_name": "Linux", "version": { "version_data": [ { "version_affected": "<", "version_name": "000dbe0bec05", "version_value": "ad27382f8495" }, { "version_value": "not down converted", "x_cve_json_5_version_data": { "versions": [ { "version": "6.4", "status": "affected" }, { "version": "0", "lessThan": "6.4", "status": "unaffected", "versionType": "custom" }, { "version": "6.6.23", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.7.11", "lessThanOrEqual": "6.7.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.8.2", "lessThanOrEqual": "6.8.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.9", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ], "defaultStatus": "affected" } } ] } } ] } } ] } }, "references": { "reference_data": [ { "url": "https://git.kernel.org/stable/c/ad27382f8495f8ef6d2c66c413d756bfd13c0598", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/ad27382f8495f8ef6d2c66c413d756bfd13c0598" }, { "url": "https://git.kernel.org/stable/c/8df1678c021ffeb20ef8a203bd9413f3ed9b0e9a", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/8df1678c021ffeb20ef8a203bd9413f3ed9b0e9a" }, { "url": "https://git.kernel.org/stable/c/8a2e5977cecd3cde6a0e3e86b7b914d00240e5dc", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/8a2e5977cecd3cde6a0e3e86b7b914d00240e5dc" }, { "url": "https://git.kernel.org/stable/c/fd5860ab6341506004219b080aea40213b299d2e", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/fd5860ab6341506004219b080aea40213b299d2e" } ] }, "generator": { "engine": "bippy-a5840b7849dd" } }