November 2023 - Linux-stable-mirror

[PATCH bpf v3 0/2] bpf: Fix incorrect immediate spill

by Hao Sun

Immediate is incorrectly cast to u32 before being spilled, losing sign information. The range information is incorrect after load again. Fix immediate spill by remove the cast. The second patch add a test case for this. Signed-off-by: Hao Sun <sunhao.th(a)gmail.com> --- Changes in v3: - Change the expected log to fix the test case - Link to v2: https://lore.kernel.org/r/20231101-fix-check-stack-write-v2-0-cb7c17b869b0@… Changes in v2: - Add fix and cc tags. - Link to v1: https://lore.kernel.org/r/20231026-fix-check-stack-write-v1-0-6b325ef3ce7e@… --- Hao Sun (2): bpf: Fix check_stack_write_fixed_off() to correctly spill imm selftests/bpf: Add test for immediate spilled to stack kernel/bpf/verifier.c | 2 +- tools/testing/selftests/bpf/verifier/bpf_st_mem.c | 32 +++++++++++++++++++++++ 2 files changed, 33 insertions(+), 1 deletion(-) --- base-commit: f2fbb908112311423b09cd0d2b4978f174b99585 change-id: 20231026-fix-check-stack-write-c40996694dfa Best regards, -- Hao Sun <sunhao.th(a)gmail.com>

1 year, 3 months

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[PATCH net v2] llc: verify mac len before reading mac header

by Willem de Bruijn

From: Willem de Bruijn <willemb(a)google.com> LLC reads the mac header with eth_hdr without verifying that the skb has an Ethernet header. Syzbot was able to enter llc_rcv on a tun device. Tun can insert packets without mac len and with user configurable skb->protocol (passing a tun_pi header when not configuring IFF_NO_PI). BUG: KMSAN: uninit-value in llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline] BUG: KMSAN: uninit-value in llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111 llc_station_ac_send_test_r net/llc/llc_station.c:81 [inline] llc_station_rcv+0x6fb/0x1290 net/llc/llc_station.c:111 llc_rcv+0xc5d/0x14a0 net/llc/llc_input.c:218 __netif_receive_skb_one_core net/core/dev.c:5523 [inline] __netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5637 netif_receive_skb_internal net/core/dev.c:5723 [inline] netif_receive_skb+0x58/0x660 net/core/dev.c:5782 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555 tun_get_user+0x54c5/0x69c0 drivers/net/tun.c:2002 Add a mac_len test before all three eth_hdr(skb) calls under net/llc. There are further uses in include/net/llc_pdu.h. All these are protected by a test skb->protocol == ETH_P_802_2. Which does not protect against this tun scenario. But the mac_len test added in this patch in llc_fixup_skb will indirectly protect those too. That is called from llc_rcv before any other LLC code. It is tempting to just add a blanket mac_len check in llc_rcv, but not sure whether that could break valid LLC paths that do not assume an Ethernet header. 802.2 LLC may be used on top of non-802.3 protocols in principle. The below referenced commit shows that used to, on top of Token Ring. At least one of the three eth_hdr uses goes back to before the start of git history. But the one that syzbot exercises is introduced in this commit. That commit is old enough (2008), that effectively all stable kernels should receive this. Fixes: f83f1768f833 ("[LLC]: skb allocation size for responses") Reported-by: syzbot+a8c7be6dee0de1b669cc(a)syzkaller.appspotmail.com Signed-off-by: Willem de Bruijn <willemb(a)google.com> --- Changes v1->v2 - fix return value in llc_sap_action_send_test_r - add Fixes tag - cc: stable(a)vger.kernel.org --- net/llc/llc_input.c | 10 ++++++++-- net/llc/llc_s_ac.c | 3 +++ net/llc/llc_station.c | 3 +++ 3 files changed, 14 insertions(+), 2 deletions(-) diff --git a/net/llc/llc_input.c b/net/llc/llc_input.c index 7cac441862e21..51bccfb00a9cd 100644 --- a/net/llc/llc_input.c +++ b/net/llc/llc_input.c @@ -127,8 +127,14 @@ static inline int llc_fixup_skb(struct sk_buff *skb) skb->transport_header += llc_len; skb_pull(skb, llc_len); if (skb->protocol == htons(ETH_P_802_2)) { - __be16 pdulen = eth_hdr(skb)->h_proto; - s32 data_size = ntohs(pdulen) - llc_len; + __be16 pdulen; + s32 data_size; + + if (skb->mac_len < ETH_HLEN) + return 0; + + pdulen = eth_hdr(skb)->h_proto; + data_size = ntohs(pdulen) - llc_len; if (data_size < 0 || !pskb_may_pull(skb, data_size)) diff --git a/net/llc/llc_s_ac.c b/net/llc/llc_s_ac.c index 79d1cef8f15a9..06fb8e6944b06 100644 --- a/net/llc/llc_s_ac.c +++ b/net/llc/llc_s_ac.c @@ -153,6 +153,9 @@ int llc_sap_action_send_test_r(struct llc_sap *sap, struct sk_buff *skb) int rc = 1; u32 data_size; + if (skb->mac_len < ETH_HLEN) + return 1; + llc_pdu_decode_sa(skb, mac_da); llc_pdu_decode_da(skb, mac_sa); llc_pdu_decode_ssap(skb, &dsap); diff --git a/net/llc/llc_station.c b/net/llc/llc_station.c index 05c6ae0920534..f506542925109 100644 --- a/net/llc/llc_station.c +++ b/net/llc/llc_station.c @@ -76,6 +76,9 @@ static int llc_station_ac_send_test_r(struct sk_buff *skb) u32 data_size; struct sk_buff *nskb; + if (skb->mac_len < ETH_HLEN) + goto out; + /* The test request command is type U (llc_len = 3) */ data_size = ntohs(eth_hdr(skb)->h_proto) - 3; nskb = llc_alloc_frame(NULL, skb->dev, LLC_PDU_TYPE_U, data_size); -- 2.42.0.758.gaed0368e0e-goog

1 year, 3 months

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[PATCH bpf v1 1/2] bpf: Fix precision tracking for BPF_ALU | BPF_TO_BE | BPF_END

by Shung-Hsi Yu

BPF_END and BPF_NEG has a different specification for the source bit in the opcode compared to other ALU/ALU64 instructions, and is either reserved or use to specify the byte swap endianness. In both cases the source bit does not encode source operand location, and src_reg is a reserved field. backtrack_insn() currently does not differentiate BPF_END and BPF_NEG from other ALU/ALU64 instructions, which leads to r0 being incorrectly marked as precise when processing BPF_ALU | BPF_TO_BE | BPF_END instructions. This commit teaches backtrack_insn() to correctly mark precision for such case. While precise tracking of BPF_NEG and other BPF_END instructions are correct and does not need fixing, this commit opt to process all BPF_NEG and BPF_END instructions within the same if-clause to better align with current convention used in the verifier (e.g. check_alu_op). Fixes: b5dc0163d8fd ("bpf: precise scalar_value tracking") Cc: stable(a)vger.kernel.org Reported-by: Mohamed Mahmoud <mmahmoud(a)redhat.com> Closes: https://lore.kernel.org/r/87jzrrwptf.fsf@toke.dk Tested-by: Toke Høiland-Jørgensen <toke(a)redhat.com> Tested-by: Tao Lyu <tao.lyu(a)epfl.ch> Acked-by: Eduard Zingerman <eddyz87(a)gmail.com> Signed-off-by: Shung-Hsi Yu <shung-hsi.yu(a)suse.com> --- kernel/bpf/verifier.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 873ade146f3d..ba9aee3a4269 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3426,7 +3426,12 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx, if (class == BPF_ALU || class == BPF_ALU64) { if (!bt_is_reg_set(bt, dreg)) return 0; - if (opcode == BPF_MOV) { + if (opcode == BPF_END || opcode == BPF_NEG) { + /* sreg is reserved and unused + * dreg still need precision before this insn + */ + return 0; + } else if (opcode == BPF_MOV) { if (BPF_SRC(insn->code) == BPF_X) { /* dreg = sreg or dreg = (s8, s16, s32)sreg * dreg needs precision after this insn -- 2.42.0

1 year, 3 months

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[PATCH] LoongArch: Mark __percpu functions as always inline

by Nathan Chancellor

A recent change to the optimization pipeline in LLVM reveals some fragility around the inlining of LoongArch's __percpu functions, which manifests as a BUILD_BUG() failure: In file included from kernel/sched/build_policy.c:17: In file included from include/linux/sched/cputime.h:5: In file included from include/linux/sched/signal.h:5: In file included from include/linux/rculist.h:11: In file included from include/linux/rcupdate.h:26: In file included from include/linux/irqflags.h:18: arch/loongarch/include/asm/percpu.h:97:3: error: call to '__compiletime_assert_51' declared with 'error' attribute: BUILD_BUG failed 97 | BUILD_BUG(); | ^ include/linux/build_bug.h:59:21: note: expanded from macro 'BUILD_BUG' 59 | #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed") | ^ include/linux/build_bug.h:39:37: note: expanded from macro 'BUILD_BUG_ON_MSG' 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) | ^ include/linux/compiler_types.h:425:2: note: expanded from macro 'compiletime_assert' 425 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^ include/linux/compiler_types.h:413:2: note: expanded from macro '_compiletime_assert' 413 | __compiletime_assert(condition, msg, prefix, suffix) | ^ include/linux/compiler_types.h:406:4: note: expanded from macro '__compiletime_assert' 406 | prefix ## suffix(); \ | ^ <scratch space>:86:1: note: expanded from here 86 | __compiletime_assert_51 | ^ 1 error generated. If these functions are not inlined, the BUILD_BUG() in the default case cannot be eliminated since the compiler cannot prove it is never used, resulting in a build failure due to the error attribute. Mark these functions as __always_inline so that the BUILD_BUG() only triggers when the default case genuinely cannot be eliminated due to an unexpected size. Cc: <stable(a)vger.kernel.org> Closes: https://github.com/ClangBuiltLinux/linux/issues/1955 Fixes: 46859ac8af52 ("LoongArch: Add multi-processor (SMP) support") Link: https://github.com/llvm/llvm-project/commit/1a2e77cf9e11dbf56b5720c607313a5… Signed-off-by: Nathan Chancellor <nathan(a)kernel.org> --- arch/loongarch/include/asm/percpu.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/loongarch/include/asm/percpu.h b/arch/loongarch/include/asm/percpu.h index b9f567e66016..8fb857ae962b 100644 --- a/arch/loongarch/include/asm/percpu.h +++ b/arch/loongarch/include/asm/percpu.h @@ -32,7 +32,7 @@ static inline void set_my_cpu_offset(unsigned long off) #define __my_cpu_offset __my_cpu_offset #define PERCPU_OP(op, asm_op, c_op) \ -static inline unsigned long __percpu_##op(void *ptr, \ +static __always_inline unsigned long __percpu_##op(void *ptr, \ unsigned long val, int size) \ { \ unsigned long ret; \ @@ -63,7 +63,7 @@ PERCPU_OP(and, and, &) PERCPU_OP(or, or, |) #undef PERCPU_OP -static inline unsigned long __percpu_read(void *ptr, int size) +static __always_inline unsigned long __percpu_read(void *ptr, int size) { unsigned long ret; --- base-commit: 278be83601dd1725d4732241f066d528e160a39d change-id: 20231101-loongarch-always-inline-percpu-ops-cf77c161871f Best regards, -- Nathan Chancellor <nathan(a)kernel.org>

1 year, 3 months

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[PATCH v2 2/2] media: i2c: imx290: Properly encode registers as little-endian

by Alexander Stein

The conversion to CCI also converted the multi-byte register access to big-endian. Correct the register definition by using the correct little-endian ones. Fixes: af73323b97702 ("media: imx290: Convert to new CCI register access helpers") Cc: stable(a)vger.kernel.org Signed-off-by: Alexander Stein <alexander.stein(a)ew.tq-group.com> --- drivers/media/i2c/imx290.c | 42 +++++++++++++++++++------------------- 1 file changed, 21 insertions(+), 21 deletions(-) diff --git a/drivers/media/i2c/imx290.c b/drivers/media/i2c/imx290.c index 29098612813cb..c6fea5837a19f 100644 --- a/drivers/media/i2c/imx290.c +++ b/drivers/media/i2c/imx290.c @@ -41,18 +41,18 @@ #define IMX290_WINMODE_720P (1 << 4) #define IMX290_WINMODE_CROP (4 << 4) #define IMX290_FR_FDG_SEL CCI_REG8(0x3009) -#define IMX290_BLKLEVEL CCI_REG16(0x300a) +#define IMX290_BLKLEVEL CCI_REG16_LE(0x300a) #define IMX290_GAIN CCI_REG8(0x3014) -#define IMX290_VMAX CCI_REG24(0x3018) +#define IMX290_VMAX CCI_REG24_LE(0x3018) #define IMX290_VMAX_MAX 0x3ffff -#define IMX290_HMAX CCI_REG16(0x301c) +#define IMX290_HMAX CCI_REG16_LE(0x301c) #define IMX290_HMAX_MAX 0xffff -#define IMX290_SHS1 CCI_REG24(0x3020) +#define IMX290_SHS1 CCI_REG24_LE(0x3020) #define IMX290_WINWV_OB CCI_REG8(0x303a) -#define IMX290_WINPV CCI_REG16(0x303c) -#define IMX290_WINWV CCI_REG16(0x303e) -#define IMX290_WINPH CCI_REG16(0x3040) -#define IMX290_WINWH CCI_REG16(0x3042) +#define IMX290_WINPV CCI_REG16_LE(0x303c) +#define IMX290_WINWV CCI_REG16_LE(0x303e) +#define IMX290_WINPH CCI_REG16_LE(0x3040) +#define IMX290_WINWH CCI_REG16_LE(0x3042) #define IMX290_OUT_CTRL CCI_REG8(0x3046) #define IMX290_ODBIT_10BIT (0 << 0) #define IMX290_ODBIT_12BIT (1 << 0) @@ -78,28 +78,28 @@ #define IMX290_ADBIT2 CCI_REG8(0x317c) #define IMX290_ADBIT2_10BIT 0x12 #define IMX290_ADBIT2_12BIT 0x00 -#define IMX290_CHIP_ID CCI_REG16(0x319a) +#define IMX290_CHIP_ID CCI_REG16_LE(0x319a) #define IMX290_ADBIT3 CCI_REG8(0x31ec) #define IMX290_ADBIT3_10BIT 0x37 #define IMX290_ADBIT3_12BIT 0x0e #define IMX290_REPETITION CCI_REG8(0x3405) #define IMX290_PHY_LANE_NUM CCI_REG8(0x3407) #define IMX290_OPB_SIZE_V CCI_REG8(0x3414) -#define IMX290_Y_OUT_SIZE CCI_REG16(0x3418) -#define IMX290_CSI_DT_FMT CCI_REG16(0x3441) +#define IMX290_Y_OUT_SIZE CCI_REG16_LE(0x3418) +#define IMX290_CSI_DT_FMT CCI_REG16_LE(0x3441) #define IMX290_CSI_DT_FMT_RAW10 0x0a0a #define IMX290_CSI_DT_FMT_RAW12 0x0c0c #define IMX290_CSI_LANE_MODE CCI_REG8(0x3443) -#define IMX290_EXTCK_FREQ CCI_REG16(0x3444) -#define IMX290_TCLKPOST CCI_REG16(0x3446) -#define IMX290_THSZERO CCI_REG16(0x3448) -#define IMX290_THSPREPARE CCI_REG16(0x344a) -#define IMX290_TCLKTRAIL CCI_REG16(0x344c) -#define IMX290_THSTRAIL CCI_REG16(0x344e) -#define IMX290_TCLKZERO CCI_REG16(0x3450) -#define IMX290_TCLKPREPARE CCI_REG16(0x3452) -#define IMX290_TLPX CCI_REG16(0x3454) -#define IMX290_X_OUT_SIZE CCI_REG16(0x3472) +#define IMX290_EXTCK_FREQ CCI_REG16_LE(0x3444) +#define IMX290_TCLKPOST CCI_REG16_LE(0x3446) +#define IMX290_THSZERO CCI_REG16_LE(0x3448) +#define IMX290_THSPREPARE CCI_REG16_LE(0x344a) +#define IMX290_TCLKTRAIL CCI_REG16_LE(0x344c) +#define IMX290_THSTRAIL CCI_REG16_LE(0x344e) +#define IMX290_TCLKZERO CCI_REG16_LE(0x3450) +#define IMX290_TCLKPREPARE CCI_REG16_LE(0x3452) +#define IMX290_TLPX CCI_REG16_LE(0x3454) +#define IMX290_X_OUT_SIZE CCI_REG16_LE(0x3472) #define IMX290_INCKSEL7 CCI_REG8(0x3480) #define IMX290_PGCTRL_REGEN BIT(0) -- 2.34.1

1 year, 3 months

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Re: [PATCH 093/130] RISC-V: fix compile error from deduplicated __ALTERNATIVE_CFG_2

by Conor Dooley

Top post yada yada, I don;t care. So, I got emailed on 190 patches from you that I don't think you intended to send publicly. Greg, if you see this, this is probably already in stable and is not 6.1-stable material anyway, I just had backported some stuff to my vendor tree that is the source of this. Cheers, Conor. On Wed, Nov 01, 2023 at 05:56:25PM +0000, Saravanan.K.S wrote: > > [You don't often get email from saravanan.kadambathursubramaniyam(a)windriver.com. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ] > > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > From: Heiko Stuebner <heiko.stuebner(a)vrull.eu> > > commit 7d27a3bb961dfb59ececd2f641b09fbe7198837e from > https://github.com/linux4microchip/linux.git linux-6.1-mchp > > On the non-assembler-side wrapping alternative-macros inside other macros > to prevent duplication of code works, as the end result will just be a > string that gets fed to the asm instruction. > > In real assembler code, wrapping .macro blocks inside other .macro blocks > brings more restrictions on usage it seems and the optimization done by > commit 2ba8c7dc71c0 ("riscv: Don't duplicate __ALTERNATIVE_CFG in __ALTERNATIVE_CFG_2") > results in a compile error like: > > ../arch/riscv/lib/strcmp.S: Assembler messages: > ../arch/riscv/lib/strcmp.S:15: Error: too many positional arguments > ../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "886:" > ../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "887:" > ../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "886:" > ../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "887:" > ../arch/riscv/lib/strcmp.S:15: Error: backward ref to unknown label "886:" > ../arch/riscv/lib/strcmp.S:15: Error: attempt to move .org backwards > > Wrapping the variables containing assembler code in quotes solves this issue, > compilation and the code in question still works and objdump also shows sane > decompiled results of the affected code. > > Fixes: 2ba8c7dc71c0 ("riscv: Don't duplicate __ALTERNATIVE_CFG in __ALTERNATIVE_CFG_2") > Signed-off-by: Heiko Stuebner <heiko.stuebner(a)vrull.eu> > Reviewed-by: Palmer Dabbelt <palmer(a)rivosinc.com> > Reviewed-by: Andrew Jones <ajones(a)ventanamicro.com> > Link: https://lore.kernel.org/r/20230105192610.1940841-1-heiko@sntech.de > Cc: stable(a)vger.kernel.org > Signed-off-by: Palmer Dabbelt <palmer(a)rivosinc.com> > Signed-off-by: Conor Dooley <conor.dooley(a)microchip.com> > Signed-off-by: Saravanan.K.S <saravanan.kadambathursubramaniyam(a)windriver.com> > --- > arch/riscv/include/asm/alternative-macros.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/riscv/include/asm/alternative-macros.h b/arch/riscv/include/asm/alternative-macros.h > index 7226e2462584..2c0f4c887289 100644 > --- a/arch/riscv/include/asm/alternative-macros.h > +++ b/arch/riscv/include/asm/alternative-macros.h > @@ -46,7 +46,7 @@ > > .macro ALTERNATIVE_CFG_2 old_c, new_c_1, vendor_id_1, errata_id_1, enable_1, \ > new_c_2, vendor_id_2, errata_id_2, enable_2 > - ALTERNATIVE_CFG \old_c, \new_c_1, \vendor_id_1, \errata_id_1, \enable_1 > + ALTERNATIVE_CFG "\old_c", "\new_c_1", \vendor_id_1, \errata_id_1, \enable_1 > ALT_NEW_CONTENT \vendor_id_2, \errata_id_2, \enable_2, \new_c_2 > .endm > > -- > 2.40.0 >

1 year, 3 months

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[for-next][PATCH 12/12] eventfs: Use simple_recursive_removal() to clean up dentries

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> Looking at how dentry is removed via the tracefs system, I found that eventfs does not do everything that it did under tracefs. The tracefs removal of a dentry calls simple_recursive_removal() that does a lot more than a simple d_invalidate(). As it should be a requirement that any eventfs_inode that has a dentry, so does its parent. When removing a eventfs_inode, if it has a dentry, a call to simple_recursive_removal() on that dentry should clean up all the dentries underneath it. Add WARN_ON_ONCE() to check for the parent having a dentry if any children do. Link: https://lore.kernel.org/all/20231101022553.GE1957730@ZenIV/ Link: https://lkml.kernel.org/r/20231101172650.552471568@goodmis.org Cc: stable(a)vger.kernel.org Cc: Masami Hiramatsu <mhiramat(a)kernel.org> Cc: Mark Rutland <mark.rutland(a)arm.com> Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Al Viro <viro(a)zeniv.linux.org.uk> Fixes: 5bdcd5f5331a2 ("eventfs: Implement removal of meta data from eventfs") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- fs/tracefs/event_inode.c | 77 +++++++++++++++++++++++----------------- fs/tracefs/internal.h | 2 -- 2 files changed, 44 insertions(+), 35 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 0087a3f455f1..f8a594a50ae6 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -967,30 +967,29 @@ static void unhook_dentry(struct dentry *dentry) { if (!dentry) return; - - /* Keep the dentry from being freed yet (see eventfs_workfn()) */ + /* + * Need to add a reference to the dentry that is expected by + * simple_recursive_removal(), which will include a dput(). + */ dget(dentry); - dentry->d_fsdata = NULL; - d_invalidate(dentry); - mutex_lock(&eventfs_mutex); - /* dentry should now have at least a single reference */ - WARN_ONCE((int)d_count(dentry) < 1, - "dentry %px (%s) less than one reference (%d) after invalidate\n", - dentry, dentry->d_name.name, d_count(dentry)); - mutex_unlock(&eventfs_mutex); + /* + * Also add a reference for the dput() in eventfs_workfn(). + * That is required as that dput() will free the ei after + * the SRCU grace period is over. + */ + dget(dentry); } /** * eventfs_remove_rec - remove eventfs dir or file from list * @ei: eventfs_inode to be removed. - * @head: the list head to place the deleted @ei and children * @level: prevent recursion from going more than 3 levels deep. * * This function recursively removes eventfs_inodes which * contains info of files and/or directories. */ -static void eventfs_remove_rec(struct eventfs_inode *ei, struct list_head *head, int level) +static void eventfs_remove_rec(struct eventfs_inode *ei, int level) { struct eventfs_inode *ei_child; @@ -1009,13 +1008,26 @@ static void eventfs_remove_rec(struct eventfs_inode *ei, struct list_head *head, /* search for nested folders or files */ list_for_each_entry_srcu(ei_child, &ei->children, list, lockdep_is_held(&eventfs_mutex)) { - eventfs_remove_rec(ei_child, head, level + 1); + /* Children only have dentry if parent does */ + WARN_ON_ONCE(ei_child->dentry && !ei->dentry); + eventfs_remove_rec(ei_child, level + 1); } + ei->is_freed = 1; + for (int i = 0; i < ei->nr_entries; i++) { + if (ei->d_children[i]) { + /* Children only have dentry if parent does */ + WARN_ON_ONCE(!ei->dentry); + unhook_dentry(ei->d_children[i]); + } + } + + unhook_dentry(ei->dentry); + list_del_rcu(&ei->list); - list_add_tail(&ei->del_list, head); + call_srcu(&eventfs_srcu, &ei->rcu, free_rcu_ei); } /** @@ -1026,30 +1038,22 @@ static void eventfs_remove_rec(struct eventfs_inode *ei, struct list_head *head, */ void eventfs_remove_dir(struct eventfs_inode *ei) { - struct eventfs_inode *tmp; - LIST_HEAD(ei_del_list); + struct dentry *dentry; if (!ei) return; - /* - * Move the deleted eventfs_inodes onto the ei_del_list - * which will also set the is_freed value. Note, this has to be - * done under the eventfs_mutex, but the deletions of - * the dentries must be done outside the eventfs_mutex. - * Hence moving them to this temporary list. - */ mutex_lock(&eventfs_mutex); - eventfs_remove_rec(ei, &ei_del_list, 0); + dentry = ei->dentry; + eventfs_remove_rec(ei, 0); mutex_unlock(&eventfs_mutex); - list_for_each_entry_safe(ei, tmp, &ei_del_list, del_list) { - for (int i = 0; i < ei->nr_entries; i++) - unhook_dentry(ei->d_children[i]); - unhook_dentry(ei->dentry); - list_del(&ei->del_list); - call_srcu(&eventfs_srcu, &ei->rcu, free_rcu_ei); - } + /* + * If any of the ei children has a dentry, then the ei itself + * must have a dentry. + */ + if (dentry) + simple_recursive_removal(dentry, NULL); } /** @@ -1060,10 +1064,17 @@ void eventfs_remove_dir(struct eventfs_inode *ei) */ void eventfs_remove_events_dir(struct eventfs_inode *ei) { - struct dentry *dentry = ei->dentry; + struct dentry *dentry; + dentry = ei->dentry; eventfs_remove_dir(ei); - /* Matches the dget() from eventfs_create_events_dir() */ + /* + * Matches the dget() done by tracefs_start_creating() + * in eventfs_create_events_dir() when it the dentry was + * created. In other words, it's a normal dentry that + * sticks around while the other ei->dentry are created + * and destroyed dynamically. + */ dput(dentry); } diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h index 06a1f220b901..ccee18ca66c7 100644 --- a/fs/tracefs/internal.h +++ b/fs/tracefs/internal.h @@ -55,12 +55,10 @@ struct eventfs_inode { /* * Union - used for deletion * @llist: for calling dput() if needed after RCU - * @del_list: list of eventfs_inode to delete * @rcu: eventfs_inode to delete in RCU */ union { struct llist_node llist; - struct list_head del_list; struct rcu_head rcu; }; unsigned int is_freed:1; -- 2.42.0

1 year, 3 months

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[for-next][PATCH 10/12] eventfs: Delete eventfs_inode when the last dentry is freed

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> There exists a race between holding a reference of an eventfs_inode dentry and the freeing of the eventfs_inode. If user space has a dentry held long enough, it may still be able to access the dentry's eventfs_inode after it has been freed. To prevent this, have he eventfs_inode freed via the last dput() (or via RCU if the eventfs_inode does not have a dentry). This means reintroducing the eventfs_inode del_list field at a temporary place to put the eventfs_inode. It needs to mark it as freed (via the list) but also must invalidate the dentry immediately as the return from eventfs_remove_dir() expects that they are. But the dentry invalidation must not be called under the eventfs_mutex, so it must be done after the eventfs_inode is marked as free (put on a deletion list). Link: https://lkml.kernel.org/r/20231101172650.123479767@goodmis.org Cc: stable(a)vger.kernel.org Cc: Masami Hiramatsu <mhiramat(a)kernel.org> Cc: Mark Rutland <mark.rutland(a)arm.com> Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Ajay Kaher <akaher(a)vmware.com> Fixes: 5bdcd5f5331a2 ("eventfs: Implement removal of meta data from eventfs") Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- fs/tracefs/event_inode.c | 146 ++++++++++++++++++--------------------- fs/tracefs/internal.h | 2 + 2 files changed, 69 insertions(+), 79 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 8ac9abf7a3d5..0a04ae0ca8c8 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -85,8 +85,7 @@ static int eventfs_set_attr(struct mnt_idmap *idmap, struct dentry *dentry, mutex_lock(&eventfs_mutex); ei = dentry->d_fsdata; - /* The LSB is set when the eventfs_inode is being freed */ - if (((unsigned long)ei & 1UL) || ei->is_freed) { + if (ei->is_freed) { /* Do not allow changes if the event is about to be removed. */ mutex_unlock(&eventfs_mutex); return -ENODEV; @@ -276,35 +275,17 @@ static void free_ei(struct eventfs_inode *ei) void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry) { struct tracefs_inode *ti_parent; - struct eventfs_inode *ei_child, *tmp; struct eventfs_inode *ei; int i; /* The top level events directory may be freed by this */ if (unlikely(ti->flags & TRACEFS_EVENT_TOP_INODE)) { - LIST_HEAD(ef_del_list); - mutex_lock(&eventfs_mutex); - ei = ti->private; - - /* Record all the top level files */ - list_for_each_entry_srcu(ei_child, &ei->children, list, - lockdep_is_held(&eventfs_mutex)) { - list_add_tail(&ei_child->del_list, &ef_del_list); - } - /* Nothing should access this, but just in case! */ ti->private = NULL; - mutex_unlock(&eventfs_mutex); - /* Now safely free the top level files and their children */ - list_for_each_entry_safe(ei_child, tmp, &ef_del_list, del_list) { - list_del(&ei_child->del_list); - eventfs_remove_dir(ei_child); - } - free_ei(ei); return; } @@ -319,14 +300,6 @@ void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry) if (!ei) goto out; - /* - * If ei was freed, then the LSB bit is set for d_fsdata. - * But this should not happen, as it should still have a - * ref count that prevents it. Warn in case it does. - */ - if (WARN_ON_ONCE((unsigned long)ei & 1)) - goto out; - /* This could belong to one of the files of the ei */ if (ei->dentry != dentry) { for (i = 0; i < ei->nr_entries; i++) { @@ -336,6 +309,8 @@ void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry) if (WARN_ON_ONCE(i == ei->nr_entries)) goto out; ei->d_children[i] = NULL; + } else if (ei->is_freed) { + free_ei(ei); } else { ei->dentry = NULL; } @@ -962,13 +937,65 @@ struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry return ERR_PTR(-ENOMEM); } +static LLIST_HEAD(free_list); + +static void eventfs_workfn(struct work_struct *work) +{ + struct eventfs_inode *ei, *tmp; + struct llist_node *llnode; + + llnode = llist_del_all(&free_list); + llist_for_each_entry_safe(ei, tmp, llnode, llist) { + /* This dput() matches the dget() from unhook_dentry() */ + for (int i = 0; i < ei->nr_entries; i++) { + if (ei->d_children[i]) + dput(ei->d_children[i]); + } + /* This should only get here if it had a dentry */ + if (!WARN_ON_ONCE(!ei->dentry)) + dput(ei->dentry); + } +} + +static DECLARE_WORK(eventfs_work, eventfs_workfn); + static void free_rcu_ei(struct rcu_head *head) { struct eventfs_inode *ei = container_of(head, struct eventfs_inode, rcu); + if (ei->dentry) { + /* Do not free the ei until all references of dentry are gone */ + if (llist_add(&ei->llist, &free_list)) + queue_work(system_unbound_wq, &eventfs_work); + return; + } + + /* If the ei doesn't have a dentry, neither should its children */ + for (int i = 0; i < ei->nr_entries; i++) { + WARN_ON_ONCE(ei->d_children[i]); + } + free_ei(ei); } +static void unhook_dentry(struct dentry *dentry) +{ + if (!dentry) + return; + + /* Keep the dentry from being freed yet (see eventfs_workfn()) */ + dget(dentry); + + dentry->d_fsdata = NULL; + d_invalidate(dentry); + mutex_lock(&eventfs_mutex); + /* dentry should now have at least a single reference */ + WARN_ONCE((int)d_count(dentry) < 1, + "dentry %px (%s) less than one reference (%d) after invalidate\n", + dentry, dentry->d_name.name, d_count(dentry)); + mutex_unlock(&eventfs_mutex); +} + /** * eventfs_remove_rec - remove eventfs dir or file from list * @ei: eventfs_inode to be removed. @@ -1006,33 +1033,6 @@ static void eventfs_remove_rec(struct eventfs_inode *ei, struct list_head *head, list_add_tail(&ei->del_list, head); } -static void unhook_dentry(struct dentry **dentry, struct dentry **list) -{ - if (*dentry) { - unsigned long ptr = (unsigned long)*list; - - /* Keep the dentry from being freed yet */ - dget(*dentry); - - /* - * Paranoid: The dget() above should prevent the dentry - * from being freed and calling eventfs_set_ei_status_free(). - * But just in case, set the link list LSB pointer to 1 - * and have eventfs_set_ei_status_free() check that to - * make sure that if it does happen, it will not think - * the d_fsdata is an eventfs_inode. - * - * For this to work, no eventfs_inode should be allocated - * on a odd space, as the ef should always be allocated - * to be at least word aligned. Check for that too. - */ - WARN_ON_ONCE(ptr & 1); - - (*dentry)->d_fsdata = (void *)(ptr | 1); - *list = *dentry; - *dentry = NULL; - } -} /** * eventfs_remove_dir - remove eventfs dir or file from list * @ei: eventfs_inode to be removed. @@ -1043,40 +1043,28 @@ void eventfs_remove_dir(struct eventfs_inode *ei) { struct eventfs_inode *tmp; LIST_HEAD(ei_del_list); - struct dentry *dentry_list = NULL; - struct dentry *dentry; - int i; if (!ei) return; + /* + * Move the deleted eventfs_inodes onto the ei_del_list + * which will also set the is_freed value. Note, this has to be + * done under the eventfs_mutex, but the deletions of + * the dentries must be done outside the eventfs_mutex. + * Hence moving them to this temporary list. + */ mutex_lock(&eventfs_mutex); eventfs_remove_rec(ei, &ei_del_list, 0); + mutex_unlock(&eventfs_mutex); list_for_each_entry_safe(ei, tmp, &ei_del_list, del_list) { - for (i = 0; i < ei->nr_entries; i++) - unhook_dentry(&ei->d_children[i], &dentry_list); - unhook_dentry(&ei->dentry, &dentry_list); + for (int i = 0; i < ei->nr_entries; i++) + unhook_dentry(ei->d_children[i]); + unhook_dentry(ei->dentry); + list_del(&ei->del_list); call_srcu(&eventfs_srcu, &ei->rcu, free_rcu_ei); } - mutex_unlock(&eventfs_mutex); - - while (dentry_list) { - unsigned long ptr; - - dentry = dentry_list; - ptr = (unsigned long)dentry->d_fsdata & ~1UL; - dentry_list = (struct dentry *)ptr; - dentry->d_fsdata = NULL; - d_invalidate(dentry); - mutex_lock(&eventfs_mutex); - /* dentry should now have at least a single reference */ - WARN_ONCE((int)d_count(dentry) < 1, - "dentry %px (%s) less than one reference (%d) after invalidate\n", - dentry, dentry->d_name.name, d_count(dentry)); - mutex_unlock(&eventfs_mutex); - dput(dentry); - } } /** diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h index 5f60bcd69289..06a1f220b901 100644 --- a/fs/tracefs/internal.h +++ b/fs/tracefs/internal.h @@ -54,10 +54,12 @@ struct eventfs_inode { void *data; /* * Union - used for deletion + * @llist: for calling dput() if needed after RCU * @del_list: list of eventfs_inode to delete * @rcu: eventfs_inode to delete in RCU */ union { + struct llist_node llist; struct list_head del_list; struct rcu_head rcu; }; -- 2.42.0

1 year, 3 months

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[for-next][PATCH 05/12] eventfs: Remove "is_freed" union with rcu head

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> The eventfs_inode->is_freed was a union with the rcu_head with the assumption that when it was on the srcu list the head would contain a pointer which would make "is_freed" true. But that was a wrong assumption as the rcu head is a single link list where the last element is NULL. Instead, split the nr_entries integer so that "is_freed" is one bit and the nr_entries is the next 31 bits. As there shouldn't be more than 10 (currently there's at most 5 to 7 depending on the config), this should not be a problem. Link: https://lkml.kernel.org/r/20231101172649.049758712@goodmis.org Cc: stable(a)vger.kernel.org Cc: Mark Rutland <mark.rutland(a)arm.com> Cc: Andrew Morton <akpm(a)linux-foundation.org> Cc: Ajay Kaher <akaher(a)vmware.com> Fixes: 63940449555e7 ("eventfs: Implement eventfs lookup, read, open functions") Reviewed-by: Masami Hiramatsu (Google) <mhiramat(a)kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- fs/tracefs/event_inode.c | 2 ++ fs/tracefs/internal.h | 6 +++--- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 9f612a8f009d..1ce73acf3df0 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -824,6 +824,8 @@ static void eventfs_remove_rec(struct eventfs_inode *ei, struct list_head *head, eventfs_remove_rec(ei_child, head, level + 1); } + ei->is_freed = 1; + list_del_rcu(&ei->list); list_add_tail(&ei->del_list, head); } diff --git a/fs/tracefs/internal.h b/fs/tracefs/internal.h index 64fde9490f52..c7d88aaa949f 100644 --- a/fs/tracefs/internal.h +++ b/fs/tracefs/internal.h @@ -23,6 +23,7 @@ struct tracefs_inode { * @d_parent: pointer to the parent's dentry * @d_children: The array of dentries to represent the files when created * @data: The private data to pass to the callbacks + * @is_freed: Flag set if the eventfs is on its way to be freed * @nr_entries: The number of items in @entries */ struct eventfs_inode { @@ -38,14 +39,13 @@ struct eventfs_inode { * Union - used for deletion * @del_list: list of eventfs_inode to delete * @rcu: eventfs_inode to delete in RCU - * @is_freed: node is freed if one of the above is set */ union { struct list_head del_list; struct rcu_head rcu; - unsigned long is_freed; }; - int nr_entries; + unsigned int is_freed:1; + unsigned int nr_entries:31; }; static inline struct tracefs_inode *get_tracefs(const struct inode *inode) -- 2.42.0

1 year, 3 months

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[for-next][PATCH 03/12] tracing: Have the user copy of synthetic event address use correct context

by Steven Rostedt

From: "Steven Rostedt (Google)" <rostedt(a)goodmis.org> A synthetic event is created by the synthetic event interface that can read both user or kernel address memory. In reality, it reads any arbitrary memory location from within the kernel. If the address space is in USER (where CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE is set) then it uses strncpy_from_user_nofault() to copy strings otherwise it uses strncpy_from_kernel_nofault(). But since both functions use the same variable there's no annotation to what that variable is (ie. __user). This makes sparse complain. Quiet sparse by typecasting the strncpy_from_user_nofault() variable to a __user pointer. Link: https://lore.kernel.org/linux-trace-kernel/20231031151033.73c42e23@gandalf.… Cc: stable(a)vger.kernel.org Cc: Masami Hiramatsu <mhiramat(a)kernel.org> Cc: Mark Rutland <mark.rutland(a)arm.com> Fixes: 0934ae9977c2 ("tracing: Fix reading strings from synthetic events"); Reported-by: kernel test robot <lkp(a)intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202311010013.fm8WTxa5-lkp@intel.com/ Signed-off-by: Steven Rostedt (Google) <rostedt(a)goodmis.org> --- kernel/trace/trace_events_synth.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index 14cb275a0bab..846e02c0fb59 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -452,7 +452,7 @@ static unsigned int trace_string(struct synth_trace_event *entry, #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE if ((unsigned long)str_val < TASK_SIZE) - ret = strncpy_from_user_nofault(str_field, str_val, STR_VAR_LEN_MAX); + ret = strncpy_from_user_nofault(str_field, (const void __user *)str_val, STR_VAR_LEN_MAX); else #endif ret = strncpy_from_kernel_nofault(str_field, str_val, STR_VAR_LEN_MAX); -- 2.42.0

1 year, 3 months

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Linux-stable-mirror November 2023