In the Linux kernel, the following vulnerability has been resolved: jffs2: check jffs2_prealloc_raw_node_refs() result in few other places Fuzzing hit another invalid pointer dereference due to the lack of checking whether jffs2_prealloc_raw_node_refs() completed successfully. Subsequent logic implies that the node refs have been allocated. Handle that. The code is ready for propagating the error upwards. KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 1 PID: 5835 Comm: syz-executor145 Not tainted 5.10.234-syzkaller #0 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 RIP: 0010:jffs2_link_node_ref+0xac/0x690 fs/jffs2/nodelist.c:600 Call Trace: jffs2_mark_erased_block fs/jffs2/erase.c:460 [inline] jffs2_erase_pending_blocks+0x688/0x1860 fs/jffs2/erase.c:118 jffs2_garbage_collect_pass+0x638/0x1a00 fs/jffs2/gc.c:253 jffs2_reserve_space+0x3f4/0xad0 fs/jffs2/nodemgmt.c:167 jffs2_write_inode_range+0x246/0xb50 fs/jffs2/write.c:362 jffs2_write_end+0x712/0x1110 fs/jffs2/file.c:302 generic_perform_write+0x2c2/0x500 mm/filemap.c:3347 __generic_file_write_iter+0x252/0x610 mm/filemap.c:3465 generic_file_write_iter+0xdb/0x230 mm/filemap.c:3497 call_write_iter include/linux/fs.h:2039 [inline] do_iter_readv_writev+0x46d/0x750 fs/read_write.c:740 do_iter_write+0x18c/0x710 fs/read_write.c:866 vfs_writev+0x1db/0x6a0 fs/read_write.c:939 do_pwritev fs/read_write.c:1036 [inline] __do_sys_pwritev fs/read_write.c:1083 [inline] __se_sys_pwritev fs/read_write.c:1078 [inline] __x64_sys_pwritev+0x235/0x310 fs/read_write.c:1078 do_syscall_64+0x30/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x67/0xd1 Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
4.10.0-14.16~16.04.14.10.0-19.21~16.04.14.10.0-20.22~16.04.14.10.0-21.23~16.04.14.10.0-22.24~16.04.14.10.0-24.28~16.04.14.10.0-26.30~16.04.14.11.0-13.19~16.04.14.11.0-14.20~16.04.14.13.0-16.19~16.04.3+13 more5.0.0-1021.24~18.04.15.0.0-1022.25~18.04.15.0.0-1023.26~18.04.15.0.0-1024.27~18.04.15.0.0-1025.285.0.0-1027.305.3.0-1016.17~18.04.15.3.0-1017.18~18.04.15.3.0-1019.21~18.04.15.3.0-1023.25~18.04.15.3.0-1028.30~18.04.15.3.0-1030.32~18.04.15.3.0-1032.34~18.04.25.3.0-1033.355.3.0-1034.365.3.0-1035.374.15.0-1002.24.15.0-1003.34.15.0-1004.44.15.0-1008.84.15.0-1009.94.15.0-1012.124.15.0-1013.134.15.0-1014.144.15.0-1018.184.15.0-1019.19+34 more5.3.0-1007.8~18.04.15.3.0-1008.9~18.04.15.3.0-1009.10~18.04.15.3.0-1010.11~18.04.15.3.0-1012.13~18.04.15.3.0-1013.14~18.04.15.3.0-1016.17~18.04.15.3.0-1018.19~18.04.15.3.0-1019.20~18.04.15.3.0-1020.21~18.04.1+6 more4.18.0-1006.6~18.04.14.18.0-1007.7~18.04.14.18.0-1008.8~18.04.15.0.0-1012.12~18.04.24.15.0-1001.14.15.0-1003.34.15.0-1005.54.15.0-1006.64.15.0-1008.84.15.0-1009.94.15.0-1010.104.15.0-1014.144.15.0-1015.154.15.0-1017.18+28 more5.3.0-1008.9~18.04.15.3.0-1009.10~18.04.15.3.0-1010.11~18.04.15.3.0-1012.13~18.04.15.3.0-1014.15~18.04.15.3.0-1016.17~18.04.15.3.0-1017.18~18.04.15.3.0-1018.19~18.04.15.3.0-1020.22~18.04.15.3.0-1026.28~18.04.1+3 more4.15.0-1030.324.15.0-1032.344.15.0-1033.354.15.0-1034.364.15.0-1036.384.15.0-1037.394.15.0-1040.424.15.0-1041.434.15.0-1042.444.15.0-1044.46+23 more5.4.0-1025.25~18.04.15.4.0-1027.28~18.04.15.4.0-1029.31~18.04.15.4.0-1030.32~18.04.15.4.0-1032.34~18.04.15.4.0-1033.35~18.04.15.4.0-1035.37~18.04.15.4.0-1036.38~18.04.15.4.0-1037.39~18.04.15.4.0-1039.41~18.04.1+27 moreExploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:NI:NA:HCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H