--- /dev/null
+From 79d72c68c58784a3e1cd2378669d51bfd0cb7498 Mon Sep 17 00:00:00 2001
+From: Oscar Salvador <osalvador@suse.de>
+Date: Tue, 30 Jan 2024 22:04:18 +0100
+Subject: fs,hugetlb: fix NULL pointer dereference in hugetlbs_fill_super
+
+From: Oscar Salvador <osalvador@suse.de>
+
+commit 79d72c68c58784a3e1cd2378669d51bfd0cb7498 upstream.
+
+When configuring a hugetlb filesystem via the fsconfig() syscall, there is
+a possible NULL dereference in hugetlbfs_fill_super() caused by assigning
+NULL to ctx->hstate in hugetlbfs_parse_param() when the requested pagesize
+is non valid.
+
+E.g: Taking the following steps:
+
+ fd = fsopen("hugetlbfs", FSOPEN_CLOEXEC);
+ fsconfig(fd, FSCONFIG_SET_STRING, "pagesize", "1024", 0);
+ fsconfig(fd, FSCONFIG_CMD_CREATE, NULL, NULL, 0);
+
+Given that the requested "pagesize" is invalid, ctxt->hstate will be replaced
+with NULL, losing its previous value, and we will print an error:
+
+ ...
+ ...
+ case Opt_pagesize:
+ ps = memparse(param->string, &rest);
+ ctx->hstate = h;
+ if (!ctx->hstate) {
+ pr_err("Unsupported page size %lu MB\n", ps / SZ_1M);
+ return -EINVAL;
+ }
+ return 0;
+ ...
+ ...
+
+This is a problem because later on, we will dereference ctxt->hstate in
+hugetlbfs_fill_super()
+
+ ...
+ ...
+ sb->s_blocksize = huge_page_size(ctx->hstate);
+ ...
+ ...
+
+Causing below Oops.
+
+Fix this by replacing cxt->hstate value only when then pagesize is known
+to be valid.
+
+ kernel: hugetlbfs: Unsupported page size 0 MB
+ kernel: BUG: kernel NULL pointer dereference, address: 0000000000000028
+ kernel: #PF: supervisor read access in kernel mode
+ kernel: #PF: error_code(0x0000) - not-present page
+ kernel: PGD 800000010f66c067 P4D 800000010f66c067 PUD 1b22f8067 PMD 0
+ kernel: Oops: 0000 [#1] PREEMPT SMP PTI
+ kernel: CPU: 4 PID: 5659 Comm: syscall Tainted: G E 6.8.0-rc2-default+ #22 5a47c3fef76212addcc6eb71344aabc35190ae8f
+ kernel: Hardware name: Intel Corp. GROVEPORT/GROVEPORT, BIOS GVPRCRB1.86B.0016.D04.1705030402 05/03/2017
+ kernel: RIP: 0010:hugetlbfs_fill_super+0xb4/0x1a0
+ kernel: Code: 48 8b 3b e8 3e c6 ed ff 48 85 c0 48 89 45 20 0f 84 d6 00 00 00 48 b8 ff ff ff ff ff ff ff 7f 4c 89 e7 49 89 44 24 20 48 8b 03 <8b> 48 28 b8 00 10 00 00 48 d3 e0 49 89 44 24 18 48 8b 03 8b 40 28
+ kernel: RSP: 0018:ffffbe9960fcbd48 EFLAGS: 00010246
+ kernel: RAX: 0000000000000000 RBX: ffff9af5272ae780 RCX: 0000000000372004
+ kernel: RDX: ffffffffffffffff RSI: ffffffffffffffff RDI: ffff9af555e9b000
+ kernel: RBP: ffff9af52ee66b00 R08: 0000000000000040 R09: 0000000000370004
+ kernel: R10: ffffbe9960fcbd48 R11: 0000000000000040 R12: ffff9af555e9b000
+ kernel: R13: ffffffffa66b86c0 R14: ffff9af507d2f400 R15: ffff9af507d2f400
+ kernel: FS: 00007ffbc0ba4740(0000) GS:ffff9b0bd7000000(0000) knlGS:0000000000000000
+ kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+ kernel: CR2: 0000000000000028 CR3: 00000001b1ee0000 CR4: 00000000001506f0
+ kernel: Call Trace:
+ kernel: <TASK>
+ kernel: ? __die_body+0x1a/0x60
+ kernel: ? page_fault_oops+0x16f/0x4a0
+ kernel: ? search_bpf_extables+0x65/0x70
+ kernel: ? fixup_exception+0x22/0x310
+ kernel: ? exc_page_fault+0x69/0x150
+ kernel: ? asm_exc_page_fault+0x22/0x30
+ kernel: ? __pfx_hugetlbfs_fill_super+0x10/0x10
+ kernel: ? hugetlbfs_fill_super+0xb4/0x1a0
+ kernel: ? hugetlbfs_fill_super+0x28/0x1a0
+ kernel: ? __pfx_hugetlbfs_fill_super+0x10/0x10
+ kernel: vfs_get_super+0x40/0xa0
+ kernel: ? __pfx_bpf_lsm_capable+0x10/0x10
+ kernel: vfs_get_tree+0x25/0xd0
+ kernel: vfs_cmd_create+0x64/0xe0
+ kernel: __x64_sys_fsconfig+0x395/0x410
+ kernel: do_syscall_64+0x80/0x160
+ kernel: ? syscall_exit_to_user_mode+0x82/0x240
+ kernel: ? do_syscall_64+0x8d/0x160
+ kernel: ? syscall_exit_to_user_mode+0x82/0x240
+ kernel: ? do_syscall_64+0x8d/0x160
+ kernel: ? exc_page_fault+0x69/0x150
+ kernel: entry_SYSCALL_64_after_hwframe+0x6e/0x76
+ kernel: RIP: 0033:0x7ffbc0cb87c9
+ kernel: Code: 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 97 96 0d 00 f7 d8 64 89 01 48
+ kernel: RSP: 002b:00007ffc29d2f388 EFLAGS: 00000206 ORIG_RAX: 00000000000001af
+ kernel: RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ffbc0cb87c9
+ kernel: RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003
+ kernel: RBP: 00007ffc29d2f3b0 R08: 0000000000000000 R09: 0000000000000000
+ kernel: R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
+ kernel: R13: 00007ffc29d2f4c0 R14: 0000000000000000 R15: 0000000000000000
+ kernel: </TASK>
+ kernel: Modules linked in: rpcsec_gss_krb5(E) auth_rpcgss(E) nfsv4(E) dns_resolver(E) nfs(E) lockd(E) grace(E) sunrpc(E) netfs(E) af_packet(E) bridge(E) stp(E) llc(E) iscsi_ibft(E) iscsi_boot_sysfs(E) intel_rapl_msr(E) intel_rapl_common(E) iTCO_wdt(E) intel_pmc_bxt(E) sb_edac(E) iTCO_vendor_support(E) x86_pkg_temp_thermal(E) intel_powerclamp(E) coretemp(E) kvm_intel(E) rfkill(E) ipmi_ssif(E) kvm(E) acpi_ipmi(E) irqbypass(E) pcspkr(E) igb(E) ipmi_si(E) mei_me(E) i2c_i801(E) joydev(E) intel_pch_thermal(E) i2c_smbus(E) dca(E) lpc_ich(E) mei(E) ipmi_devintf(E) ipmi_msghandler(E) acpi_pad(E) tiny_power_button(E) button(E) fuse(E) efi_pstore(E) configfs(E) ip_tables(E) x_tables(E) ext4(E) mbcache(E) jbd2(E) hid_generic(E) usbhid(E) sd_mod(E) t10_pi(E) crct10dif_pclmul(E) crc32_pclmul(E) crc32c_intel(E) polyval_clmulni(E) ahci(E) xhci_pci(E) polyval_generic(E) gf128mul(E) ghash_clmulni_intel(E) sha512_ssse3(E) sha256_ssse3(E) xhci_pci_renesas(E) libahci(E) ehci_pci(E) sha1_ssse3(E) xhci_hcd(E) ehci_hcd(E) libata(E)
+ kernel: mgag200(E) i2c_algo_bit(E) usbcore(E) wmi(E) sg(E) dm_multipath(E) dm_mod(E) scsi_dh_rdac(E) scsi_dh_emc(E) scsi_dh_alua(E) scsi_mod(E) scsi_common(E) aesni_intel(E) crypto_simd(E) cryptd(E)
+ kernel: Unloaded tainted modules: acpi_cpufreq(E):1 fjes(E):1
+ kernel: CR2: 0000000000000028
+ kernel: ---[ end trace 0000000000000000 ]---
+ kernel: RIP: 0010:hugetlbfs_fill_super+0xb4/0x1a0
+ kernel: Code: 48 8b 3b e8 3e c6 ed ff 48 85 c0 48 89 45 20 0f 84 d6 00 00 00 48 b8 ff ff ff ff ff ff ff 7f 4c 89 e7 49 89 44 24 20 48 8b 03 <8b> 48 28 b8 00 10 00 00 48 d3 e0 49 89 44 24 18 48 8b 03 8b 40 28
+ kernel: RSP: 0018:ffffbe9960fcbd48 EFLAGS: 00010246
+ kernel: RAX: 0000000000000000 RBX: ffff9af5272ae780 RCX: 0000000000372004
+ kernel: RDX: ffffffffffffffff RSI: ffffffffffffffff RDI: ffff9af555e9b000
+ kernel: RBP: ffff9af52ee66b00 R08: 0000000000000040 R09: 0000000000370004
+ kernel: R10: ffffbe9960fcbd48 R11: 0000000000000040 R12: ffff9af555e9b000
+ kernel: R13: ffffffffa66b86c0 R14: ffff9af507d2f400 R15: ffff9af507d2f400
+ kernel: FS: 00007ffbc0ba4740(0000) GS:ffff9b0bd7000000(0000) knlGS:0000000000000000
+ kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
+ kernel: CR2: 0000000000000028 CR3: 00000001b1ee0000 CR4: 00000000001506f0
+
+Link: https://lkml.kernel.org/r/20240130210418.3771-1-osalvador@suse.de
+Fixes: 32021982a324 ("hugetlbfs: Convert to fs_context")
+Signed-off-by: Michal Hocko <mhocko@suse.com>
+Signed-off-by: Oscar Salvador <osalvador@suse.de>
+Acked-by: Muchun Song <muchun.song@linux.dev>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Vamsi Krishna Brahmajosyula <vamsi-krishna.brahmajosyula@broadcom.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ fs/hugetlbfs/inode.c | 6 ++++--
+ 1 file changed, 4 insertions(+), 2 deletions(-)
+
+--- a/fs/hugetlbfs/inode.c
++++ b/fs/hugetlbfs/inode.c
+@@ -1205,6 +1205,7 @@ static int hugetlbfs_parse_param(struct
+ {
+ struct hugetlbfs_fs_context *ctx = fc->fs_private;
+ struct fs_parse_result result;
++ struct hstate *h;
+ char *rest;
+ unsigned long ps;
+ int opt;
+@@ -1249,11 +1250,12 @@ static int hugetlbfs_parse_param(struct
+
+ case Opt_pagesize:
+ ps = memparse(param->string, &rest);
+- ctx->hstate = size_to_hstate(ps);
+- if (!ctx->hstate) {
++ h = size_to_hstate(ps);
++ if (!h) {
+ pr_err("Unsupported page size %lu MB\n", ps >> 20);
+ return -EINVAL;
+ }
++ ctx->hstate = h;
+ return 0;
+
+ case Opt_min_size:
projects / thirdparty / kernel / stable-queue.git / commitdiff
